Why doesn't smashing larger and larger bodies incrementally into a rocky planet create a star?

Why doesn't smashing larger and larger bodies incrementally into a rocky planet create a star?

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Let's start with a stationary Earth. If we smash a few Mercury-sized objects into the Earth, the Earth begins to accrete mass. Repeat this step with larger and larger objects, until we start impacting Jupiters into the growing Earth. If we cause an even larger planet to crash into the Earth (say, a 3-Jupiter mass object), we will eventually reach the boundary between planets and brown dwarfs. If we continue accreting more Jupiter-sized objects to the Earth, we will pass the brown-dwarf limit of 90 Jupiter masses, we will reach stellar masses. But instead of turning into a star, this object either stays molten as a "planet", blows itself apart, or even collapses into a black hole. I tested this in Universe Sandbox 2 about 20 times, and none of them coalesced into a star. Why does this happen, and would this be realistic?

Who can say for sure? I guess the physics in Universe Sandbox is not good enough.

What I would say though is that if you have a "protostar" that contains a higher proportion of heavy elements than a usual star, then the threshold for ignition of hydrogen will be lower than 75 Jupiter masses (e.g. How large can a ball of water be without fusion starting? ). If on the other hand it contains very little hydrogen (not enough to sustain a significant main sequence reaction rate), then it will be forced to rely on He, C or even O burning that require significantly higher temperatures and a much more massive object - probably in the region of 1000 Jupiter masses.

However, if you are telling us that some of your simulations collapse into a black hole at 90 Jupiter masses, that suggests that a more simple explanation is that the simulation physics is incorrect. I also think it would take a very peculiar composition indeed to avoid a nuclear burning phase prior to collapse to a black hole, even if you give the object several stellar masses of material.

Many asteroids might be remnants of 5 destroyed worlds, scientists say

In the beginning, the solar system was little more than a cloud of dust and gas. Then cold temperatures caused the center of the cloud to collapse, forming the sun. The newborn star lit up with nuclear fusion, sending light and heat out into the spinning circumstellar disk. Soon that material coalesced into gas planets, ice giants and rocky worlds, creating the solar system we know today.

For years, asteroids were thought of as the leftovers of planet formation - chunks of material that never quite made it to planet size and that were drawn into the crowded belt of rocky remnants that circles the sun between Mars and Jupiter.

But according to a study published Monday in the journal Nature Astronomy, these were once pieces of worlds, too. A vast majority of the half-million bodies in the inner asteroid belt may in fact be shrapnel from as few as five parent bodies called "planetesimals," scientists say. But the tangled orbits of those lost worlds meant they were doomed to collide, producing fragments that also collided, producing still more fragments in a cataclysmic cascade that's been going on for more than 4 billion years.

The finding doesn't only illuminate a "mystery" of the asteroid belt, said Katherine Kretke, a planetary scientist at the Southwest Research Institute who was not involved in the study. It could also help resolve a debate about the formation of the eight planets - including Earth.

"I find it really exciting that we can look back in time and potentially see evidence of what were the building blocks that built up our solar system," she said. "If we can turn back the clock and see the asteroid belt was made by these big planetesimals, that really is telling us something quite definitive about the circumstances that formed our own planet."

The study's lead author, University of Florida astronomer Stanley Dermott, didn't necessarily set out to probe a mystery of solar system formation. He and his colleagues were looking at data on the dynamics of bodies in the inner asteroid belt in hopes of figuring out what makes an object leave the belt - and potentially fly toward Earth. (For those who are concerned about asteroid collisions, rest assured that Dermott is still studying that question.)

But as Dermott began to look through a database of near-Earth objects, he noticed something strange about many large asteroids: Their orbits were inclined, or tilted, relative to the plane of the rest of the solar system.

"We couldn't think of any forces that are acting t o produce that distribution," Dermott said. On the other hand, "if a big asteroid is smashed up and it has a high inclination, then those fragments have that same inclination."

Scientists have previously known that roughly half of inner-belt asteroids belong to five "families." But Dermott and his colleagues say their analysis suggests that number is as high as 85 percent.

This finding matches other observations of the asteroid belt, said David Nesvorny, a planetary scientist at SWRI who was not involved with Dermott's study. Asteroids thought to belong to the same family tend to orbit in clusters and have similar chemical compositions.

There's an important, if apparent, implication of the idea that asteroids are actually fragments of larger bodies: "It means asteroids are born big," Nesvorny said.

That finding may help resolve a question about planet formation that has baffled scientists for years. According to the traditional story of the origin of the solar system, the planets formed slowly from accretion, as particles in the circumstellar disk clumped together to great pebbles, then slightly larger spheres, on and on until they reached their current size.

But when scientists try to re-create this story with computer models, it breaks down. Rather than growing, these incipient planets tend to splinter after reaching pebble size. How could this process result in bodies the size of those in the asteroid belt, let alone whole planets?

Enter the "born big" hypothesis. Nesvorny and many others now think that gravity kicks in once clumps in the circumstellar disk reach the pebble stage, swiftly pulling together massive amounts of material to form a huge new planet. In the inner solar system, this produced small, rocky planets such as Earth farther from the sun, we got gas giants.

But in the space between Mars and Jupiter, the tremendous gravity of the solar system's largest planet may have made it difficult to grow a large object, Nesvorny said. The smaller bodies that did emerge, which were probably a tenth of the size of a planet such as Earth, could not have survived the ensuing chaos and collisions they broke apart and formed the asteroid belt we know today.

Some questions remain about this theory. Tim McCoy, a geologist at the Smithsonian's National Museum of Natural History, pointed out that most meteorites that fall to Earth don't look like they come from large parent bodies. And Kretke suggested that the theory might work better if there were a few dozen parent bodies, rather than just five.

Meanwhile, Nesvorny noted that the inner belt is home to only a tenth of all asteroids - he'd hope to see the analysis applied to the rest of the asteroid belt.

Dermott said he and his colleagues plan to address that question next. And some day, he added, the research may be applied to other solar systems. Astronomers have found evidence for asteroid belts around Vega and Fomalhaut, stars just a couple dozen light-years away.

"That's the next big step, and it's happening in our lifetimes," Dermott said. "The whole business of formation and evolution of planets and the question of 'What do we need to form an Earthlike planet elsewhere?' is something we can finally discuss in meaningful terms."

What Do We Really Understand About Planetary Formation?

It’s fair to say that there are a lot of gaps to fill in our knowledge of exoplanetary bodies, and 2013 proved to be a good year for bizarre discoveries. From a planet found with no star in sight, to a gas giant orbiting at an unfathomable distance, to a system containing an orbital plane 45 degrees out of whack, the list seems endless. As 2014 kicks off, we can expect no slowing down of these unusual discoveries from planet hunting teams around the world, on top of the months of Kepler data still queuing up for analysis. This opens up the topic of how these extraordinary bodies came to be, and begs the question, ‘what do we really understand about planetary formation?’

First of all, we need to imagine the early disk environment around a newly born star. The protoplanetary disk contains lots of dust and gas left over from the initial collapse of the interstellar cloud from which the star forms. Both the star and the disk rotate about a common centre of gravity, and it is the rotating debris, ranging in size from an angstrom up to a centimetre, that can evolve in the disk to form planets.

Artist Impression of Planetary Formation, courtesy of NASA

There are two widely held theories for how giant gas planets can form: core accretion and disk instability. Core accretion occurs from the collision and coagulation of solid particles into gradually larger bodies until a massive enough planetary embryo is formed (10-20 Earth masses) to accrete a gaseous envelope. Disk instability, on the other hand, describes the process by which a massive disk rapidly cools, causing it to fragment into planet-sized, self-gravitating clumps. Both theories can be used to define the presence of giant planets, but there are a few pitfalls in these explanations and a plethora of planets that neither theory alone can seem to justify. Let’s look in more detail.

The primary accepted mechanism of planet formation is our first theory, core accretion, which is best described in several stages. During the first step, material in the disk collides and aggregates to form small centimetre to metre sized clumps of matter. The clumps then grow further by smashing and sticking together, leading to the gradual coagulation of kilometre-sized planetesimals. Some of these large bodies are massive enough that runaway accretion begins, resulting in the rapid formation of planetary embryos. Here there is a distinction between the formation of terrestrial and gaseous planets. Near the star, heavier metallic elements begin to condense at hotter temperatures and violent collisions and mergers can eventually result in the production of terrestrial planets. The bodies remain relatively small due to the amount of material found in the inner disk, and explains why the terrestrial planets in our solar system lie closest to the Sun. Farther out from the star beyond the snow line, embryos form from a mix of rocky, metallic and also a considerable amount of less dense icy material. At such cool temperatures, hydrogen and helium are able to condense and build to form much larger bodies. Around 10 Earth masses, the planet then possesses enough gravitational attraction to accrete a gaseous atmosphere of hydrogen and helium, a process which continues until all the gas in the planet’s vicinity is exhausted. This describes why the planets in the outer Solar System predominantly consist of lighter elements and are able to acquire such large atmospheres.

Artist Impression of Accretion. Image Credit: Alan Brandon/Nature

However, this mechanism struggles to explain massive planets forming at large distances from a star. This has led to HD 106906 b, whose orbit is 650 times greater than the Earth’s orbit around the Sun, to be proposed as forming independently from the star altogether! A problem closer to home is the extremely long time-scale required for Neptune and Uranus to form a core through accretion, which is estimated to be around 10 million years. Since the gas and dust in the protoplanetary disk probably only lasted for a few million years, this poses quite an issue. Newer accretion models may be able to account for their formation within a short enough timescale, but this is still a challenging and ambiguous area. Alternatively, could our ice giants have formed via a different mechanism?

The Solar System. Image Credit: International Astronomical Union

A different theory of giant planet formation is via disk instability a less popular, but still plausible, explanation. This mechanism requires no direct interactions between solids whatsoever, just the condensing of gas and dust in the planetary disk. During the very early stages of a protoplanetary disk’s formation, if rapid cooling occurs in the order of an orbital timescale, material is thought to fragment into bound objects. These fragments would then condense further into the gaseous planets we observe. This theory provides an explanation of planet formation that would occur within a very short (few thousand years) timeframe, and can also be used to explain the presence of large gaseous planets near to or very far from the star. However, whether a disk could cool quickly enough to fragment on an orbital timescale is hotly debated. It could be that it is only a possibility at very large orbital radii.

With two competing theories for how the most massive planets form, we still have a lot to learn about the evolution of the different systems we observe, especially our own! It is likely that the formation mechanism is dependent on the system, and that both theories could work within different regimes. But neither of these theories seems to explain the presences of hot Jupiters gas giants that orbit incredibly close to their host stars with periods of just a few days. It is believed that at such close proximity to the star, temperatures would simply be too high for the planet to retain its gaseous envelope during formation, which is where the idea of planetary migration really came to light. This suggests that perhaps where we observe a planet now isn’t really where it originally formed at all.

Check back soon for my next post discussing the different theories of planetary migration.

Triton: A subsurface ocean?

Computer-generated montage of Triton and Neptune, using images from the Voyager 2 flyby. Credit: NASA/JPL/USGS

Neptune's largest moon Triton is most likely a captured Kuiper Belt Object. The capture of icy Triton and the subsequent taming of its orbit likely led to the formation of a subsurface ocean through tidal heating. New research suggests that this ocean could still exist today.

Triton was discovered in 1846 by the British astronomer William Lassell, but much about Neptune's largest moon still remains a mystery. A Voyager 2 flyby in 1989 offered a quick peak at the satellite, and revealed a surface composition comprised mainly of water ice. The moon's surface also had nitrogen, methane, and carbon dioxide. As Triton's density is quite high, it is suspected that it has a large core of silicate rock. It is possible that a liquid ocean could have formed between the rocky core and icy surface shell, and scientists have investigated if this ocean could have survived until now.

Captured from the Kuiper Belt

Triton has a unique property among large solar system moons it has a retrograde orbit. Planets form from a circumstellar disc of dust and gas that surrounds a young star. This disc circles the star in one direction, and thus the planets and their moons must also orbit in this same direction. These orbits are known as prograde, and a rogue object that orbits backwards is said to be in a retrograde orbit. The retrograde orbit of Triton means that it most likely did not form around Neptune.

The early Solar System was a place of dynamic violence, with many bodies changing orbits and crashing into each other. Triton likely originated in the Kuiper Belt, beyond the orbit of Neptune, and was sent hurtling inwards until it was captured by Neptune's gravity. Directly after capture, the moon would have been in a highly elliptical, eccentric orbit. This type of orbit would have raised large tides on the moon, and the friction of these tides would have caused energy to be lost. The energy loss is converted into heat within the moon, and this heat can melt some of the icy interior and form an ocean beneath the ice shell. The energy loss from tides is also responsible for gradually changing Triton's orbit from an ellipse to a circle.

Friction from tides is not the only source of heat within a terrestrial body there is also radiogenic heating. This is heat that is caused by the decay of radioactive isotopes within a moon or planet, and this process can create heat for billions of years.

Radiogenic heating contributes several times more heat to Triton's interior than tidal heating however this heat alone is not sufficient to keep the subsurface ocean in a liquid state over 4.5 billion years. However, tidal dissipation causes heat to be concentrated at the bottom of the ice shell, which impedes the growth rate of the ice and effectively acts as a tidal-heated blanket. This tidal dissipation is stronger for larger values of eccentricity, meaning it would have played a major role in heating Triton in the past.

One model of Triton’s interior. 70 to 80 percent rock (1), with the remainder being water ice (2) and an outer layer of methane and nitrogen ice (3). This is also believed to be the general interior configuration for the ice dwarf Pluto. Credit: Wikipedia

"While the concentration of tidal dissipation near the bottom of ice shells was known for some time, we believe our work is the first to demonstrate that it indeed controls the rate of freezing and sustainability of subsurface oceans," says Saswata Hier-Majumder at the University of Maryland. "Radiogenic heating, in comparison, heats up the shell uniformly, and thus doesn't have as disproportionate an influence as tidal dissipation does."

The exact point in time when Triton was captured by Neptune, along with the length of the time it took the orbit to become circularized are unknown. Triton's orbit is currently almost exactly circular. Investigating how the shape of the orbit evolved through time is important to determine the level of tidal heating that occurred, and thus if the subsurface ocean could still exist today.

As Triton cools, the ice sheet will grow to engulf the underlying ocean. The new research calculates how the thickness of the ice shell can influence the tidal dissipation and thus the crystallization of the subsurface ocean. If the ice shell is thin, then the tidal forces will have a more pronounced effect and increase the heating. If the shell is thick, then the moon becomes more rigid and less tidal heating will occur.

"I think it is extremely likely that a subsurface ammonia-rich ocean exists in Triton," says Hier-Majumder. "[But] there are a number of uncertainties in our knowledge of Triton's interior and past which makes it difficult to predict with absolute certainty."

For instance, the exact size of Triton's rocky core is unknown. If the core turns out to be larger than the value used in the calculations, then there will be more radiogenic heating, with extra heating increasing the size of any existing ocean. The depth of the ocean also may not be constant across the moon, as tidal dissipation concentrates energy near the poles, meaning that an ocean would likely be deeper there. In addition, recent calculations estimate that icy bodies in the outer Solar System could be comprised of up to 15 percent ammonia. Ammonia-rich volatile material works to lower the temperature at which a solid turns to a liquid, and the presence of such volatiles may also help the persistence of a liquid layer beneath the ice.

Computer model of the Kuiper Belt, where Triton is thought to have originated. Credit: Minor Planet Center/Murray and Dermott

Subsurface oceans on icy Solar System bodies could provide potential habitats for primitive extraterrestrial life. Jupiter's moon Europa is currently the leading candidate for such a habitat, although there is still much debate about this. The probability of life existing within the depths of Triton's ocean is much smaller than for Europa, but it still can't be completely ruled out.

The ammonia that is likely present in Triton's subsurface ocean might act to lower the freezing point of water, thus making it more suitable for life. The temperature of the ocean is still probably around 176 K (minus 97 C, or minus 143 F), which would slow down biochemical reactions significantly, and impede evolution. However terrestrial enzymes have been found to speed up biochemical reactions down to temperatures of 170 K.

Another more remote possibility is that Triton could host silicon-based life, assuming that silicon can actually be used as a foundation for life instead of carbon. Silanes, which are structural analogues of hydrocarbons, could be used as a building block for life under the right conditions. The frigid temperatures and the limited abundance of carbon on Triton could be suitable for silicon-based life, but there isn't enough known about the behavior of silanes in such unusual conditions to firmly state that such life could exist.

The research by Jodi Gaeman, Saswata Hier-Majumder, and James Roberts was published in the August issue of the journal Icarus.

Option 1, take what you need, planets disassemble

When it comes to specific elements, then definitely there is a reason to mess with whole planet, not necessary do that but if civilization do not have tech to fuse elements easily(this is rather knowledge challenge then energy challenge) it may have sense. But we have force, me not thinks, me dissemble planet, hugh hugh, rrr - besides it's fun, why not.

Disassembly may be done in different ways evaporating by focusing light-energy on surface of planet (some one suggested moving planet that way, man think again ISP will not help here, just imagine what it means for a planet, just magma ball, not a planet)

It may be more gently dissemble, which is more energy efficient and more control over stuff, less mess and less after work.

But evaporating is the easy way to estimate max energy we need for the process.
Disassemble Venus will take: mass_kg*E(escape velocity, 1kg)/Power(sun, 1sec)/Seconds_in_year

(4.867*10^24 * 10360^2/2)/(3.828*10^26)/(365*24*3600) == 0.022 years or 8 days

This is rough estimation, which isn't counting escape velocity changes because of planet mass loss, but it also not counts efficiency of process, which is less then 100% because loosing energy by heated plasma trough electromagnetic waves emission. But overall I'm ok with that number.

After 13 Years At Saturn, the Greatest Space Mission of Our Time Is Coming to an End

The Cassini spacecraft spent 13 years orbiting Saturn. It revealed the planet and its rings in striking detail, found liquid around every corner, and invigorated the idea that alien life not only exists, but could be right on our doorstep.

A strange device sits on the end table, a few dozen vertical light strips around a thicker column in the center, like a tall model carousel. Light trickles down the strips, then up. On the center column, the names of spacecraft scroll by on an LED display: VOYAGER. MER-B (for Mars Exploration Rover B, better known as Opportunity).

"This is connected to the Deep Space Network," says Charles Elachi, professor emeritus of planetary science at Caltech and the director of NASA's Jet Propulsion Laboratory from 2001 to 2016. "When you see light coming down, that means you are receiving data from the satellite, and when you see light going up, that means you are sending commands."

The Deep Space Network consists of three stations of enormous radio telescope receivers placed around the globe in California, Spain, and Australia. This way, NASA can communicate with any of its spacecraft at any time. The control center is right here in Pasadena. Whenever the network talks to a spacecraft, the electric apparatus in Elachi's office lights up. His foot-tall model is a desktop version of a room-sized DSN indicator at JPL, down the road from Caltech. The device was a gift to Elachi after he retired as director of the renowned NASA lab.

The white carousel never stays dark for more than a few seconds. And every now and then, CASSINI floats across the central column, indicating a connection with the bus-sized spacecraft that has been orbiting Saturn for the last 13 years. "From just the breadth of scientific discoveries and breadth of what it looked at, it's probably the richest mission ever undertaken by NASA," Elachi says.

But Cassini will not light up his end table contraption for much longer. On Friday, September 15, the Cassini spacecraft will fly into the atmosphere of Saturn and burn up among the high clouds, never again to talk to Earth.

Where Spring Lasts 7 Years

Launched on October 15, 1997, Cassini traveled for six years and 261 days before reaching Saturn. Though the sixth planet lies an average of 890 million miles from Earth, Cassini flew some 2.2 billion miles to get there via the scenic route: orbiting the sun to fly by Venus twice, then Earth, then to a gravity assist maneuver at Jupiter before reaching its destination. The craft has been orbiting the ringed planet since July 1, 2004, studying Saturn's fascinating moons, tiny ring particles, and turbulent atmospheric storms-including a gargantuan hexagonal vortex at the north pole that could swallow the Earth whole.

It has been a journey of unprecedented discovery. "It may go down as one of NASA's greatest planetary missions, simply because we've had a fire hose of data come back over 13 years," says Linda Spilker, Cassini Project Scientist. Spilker, a veteran of the Voyager mission, has been working on Cassini for decades, yet you need only ask her about the composition of Saturn's great rings or the icy geysers erupting from Enceladus, and the sparkle of discovery lights up in her eyes. "We have literally rewritten the textbooks about the Saturn system," she says.

The mission began with a daredevil flight. Cassini entered Saturn's orbit by flying up through the rings, a maneuver that required the spacecraft to point its radio dish away from Earth and use it as a shield to block any debris that might hit the craft. Elachi called the orbital insertion "the most tense" part of the entire mission.

"I remember very clearly we were in the mission operation room, and we were coming close, you know, to fire the engine, and here we have an engine which we have fired only once over seven years, and it had to work," the former JPL director recalls. "You can imagine the tension that was in the room, in the mission operation room when we were waiting to get the signal that the engine had fired."

Thirteen years and two months later, and the Cassini team has watched Saturn go through nearly two whole Saturnian seasons. One trip around the sun for Saturn takes about 29 Earth years, meaning each season lasts a little more than 7 years. Cassini arrived during wintertime in the planet's northern hemisphere, but winter faded into spring shortly after the conclusion of the spacecraft's primary mission in 2008.

Cassini earned two extensions to keep it going. During the two-year Equinox Mission, so-named because it included the spring Equinox of Saturn in August 2009, scientists glimpsed exactly how far icicle spires and pillars stretched above and below the rings of Saturn, as evidenced by their shadows as the sunlight hit the rings directly. The second mission extension came in February 2010-the Solstice Mission. This seven-year extension of science operations would go on to study the Saturn system until shortly after its summer solstice, the longest day in Saturn's northern hemisphere and the shortest in the south. The Solstice Mission shall be Cassini's final mission, and it is drawing to a close.

The Grand Finale of Cassini, now under way, involves a series of 22 orbits that send the spacecraft in between the great gas planet and its majestic rings, an area of the solar system that had never been visited before. Cassini has been beaming back precious images of the planet's surface and rings in unprecedented detail. It will continue to transmit data on September 15 until the spacecraft burns up in the Saturnian sky, forever to remain a part of the planet.

But when Cassini first arrived at Saturn back in 2004, it had another target in its sights: the great moon of Titan, one of the most marvelous places in the solar system.

Mountains of Ice, Seas of Methane

Titan, a moon larger than the planet Mercury, has been shrouded in mystery for centuries. The largest moon of Saturn was discovered in 1655 by Dutch astronomer Christiaan Huygens. It was the sixth moon ever discovered, following our own and the four Galilean moons around Jupiter.

The Pioneer 11 spacecraft visited in 1979 and revealed Saturn's largest moon to be cold, but blanketed with a thick atmosphere. Voyager 1 flew by at about 4,000 miles from the moon in 1980 to measure the composition and pressure of Titan's nitrogen-rich atmosphere. Although it could not peer through the atmospheric haze, Voyager's readings suggested that the surface of Titan could support channels and even lakes of liquid methane.

Cassini went to find out for sure, not only by mapping the moon with radar instruments, but also by carrying a buddy probe. The mothership deployed a small lander built by the European Space Agency called Huygens, named for Titan's discoverer. The craft would land on the mysterious moon using parachutes to slow down in the thick atmosphere.

When Huygens landed on Titan in January 2005, it became the most distant planetary landing ever achieved by humankind-a record the probe will likely retain for years or even decades. Images from Huygens' landing on Titan revealed a dynamic world of ice mountains laced with flowing channels of liquid hydrocarbons. Years of radar and spectroscopy observations from Cassini have pinpointed large hydrocarbon oceans around the poles and measured an active weather cycle of evaporation and rain. It's similar to Earth-except the rocks on Titan are made of water ice and the rains are liquid methane.

"It has the same cycle that you see on our planet," says Elachi, who studied Cassini's radar data of Titan. "You have clouds. They have rain. You have rivers. You have lakes. It evaporates, goes up, but it's all made of organic material, you know, ethane and methane. It's kind of similar to gasoline."

Planetary scientists say that Titan today could be similar to what Earth was like billions of years ago, before life took root and transformed our home planet. If this is true, then perhaps Titan will be habitable in hundreds of millions of years. Perhaps the very first processes, the first primordial mixings needed to spark life, are already underway beneath the smoggy nitrogen atmosphere. Scientists believe there is ample energy and heat for a liquid water ocean under the methane lakes and icy outer crust of the giant moon. Perhaps there is even life on Titan right now.

"I wouldn't be surprised if we can find some kind of life on Titan that is different than the life here," Elachi says. "It might be based on carbon and hydrocarbon. And Titan is much colder, so it might have to be a different kind of life that adapts to it." You wouldn't think life could survive in such extreme conditions, he says, and yet it thrives in locations on Earth that seem entirely inhospitable, such as the deepest depths of the ocean and even in burning pools of acid in the desert. "So it's not crazy. Let's put it that way. We don't have any proof, and we don't have an example, but it's not crazy to think that there might be some form of organic life on Titan."

In 2017, the prospect of life on Titan became even more exciting as the Cassini team discovered a chemical on the large moon, vinyl cyanide, has the physical properties required to form cell membranes. But when it comes to life, Titan may not be the best place to look, even in the Saturn system.

10,000-Foot Geysers

Titan's smaller neighbor Enceladus is about 314 miles wide, making it only about 4 percent the size of Earth. Yet this small moon captured the imagination of the world in 2005 when Cassini photographed something astonishing on the icy surface. Enceladus images revealed geysers of water vapor, ice, and other particles erupting from the surface of the moon thousands of feet out into space. The science team was stunned.

"You have water shooting out of that planet [Enceladus] up to literally tens of thousands of feet," says Elachi. "So just imagine you are standing at Yellowstone and you see a geyser which goes all the way up to where a jet airline is flying."

The original Cassini mission included just three flybys of Enceladus, previously thought to be a dull ball of solid ice. After the plumes were spotted, the Cassini team rewrote mission objectives, changed flight trajectories, and now Cassini has conducted 22 close flybys of Enceladus. By 2015, the team had confirmed that the plumes didn't come from an isolated warm reservoir of water, but a global subsurface ocean that envelops the moon underneath roughly 20 miles of icy crust.

The Enceladus flybys included multiple passes through the watery plumes themselves, including one that saw the spacecraft fly within 30 miles of the surface of the moon. Cassini was not outfitted to study these particles directly-no one even knew the geysers existed before the spacecraft's arrival-but scientists were able to make good use of two tools on the craft.

The breakthrough came in April 2017, when the science team announced that Cassini found evidence of hydrothermal vents on Enceladus-great volcanic fissures in the seafloor that release geothermal heat and abundant nutrients into the water. The spacecraft detected abundant molecular hydrogen in the plumes of Enceladus, an indication of vents, using its Ion and Neutral Mass Spectrometer (INMS) designed to sample gaseous materials in Titan's atmosphere. The science team also found nano-silica grains in the plumes that only form in water near the boiling point using Cassini's Cosmic Dust Analyzer (CDA), an instrument designed primarily for Saturn's rings to analyze particles up to one-thousandth of a millimeter, the size of smoke particles.

On Earth, hydrothermal vents support entire ecosystems of microbes as well as macro-level life including tube worms, crabs, and small fish, all living at depths in the ocean where no sunlight penetrates and the pressure is high enough to crush most submarines. Some abiogenesists-people who study how organic chemical reactions could spark biological life-think the very first life on Earth formed around these deep ocean vents.

Unlike Titan, everything that we consider a prerequisite for life on Earth is also found on Saturn's small watery moon. "Unfortunately, Cassini doesn't have the instruments to make the measurements to look for those big molecules and to look for evidence of life," says Spilker. "So this means we have to go back."

Spilker is currently working on a mission proposal for NASA's New Frontiers program. It would be called the Enceladus Life Finder, or ELF. The spacecraft would orbit Saturn and make multiple close flybys of Enceladus to directly sample the plumes with instruments that could identify larger particles, such as fatty acids or amino acids, that could be indicative of life.

"The mission is a series of orbits through the plume of Enceladus carrying the instruments that you would need to sample it and make the measurements to better characterize the ocean of Enceladus," says Spilker. "Then make some key measurements to try and answer the question: Is there life in the ocean of Enceladus?"

Although Titan and Enceladus are the most tantalizing of Saturn's moons, Cassini has revealed strange and marvelous facts about many of the gas giant's 62 confirmed natural satellites. The biggest by radius are Titan, Rhea, Iapetus, Dione, Tethys, Enceladus, and Mimas. Most of these worlds have surface crusts of ice and rock, and some, like Rhea and Dione, are thought to harbor subterranean oceans similar to Enceladus.

A great crater on Mimas, the smallest object in the solar system known to be spherical due to self-gravitation, makes the little world resemble the Death Star. Iapetus has a massive equatorial ridge-reaching heights of more than 12 miles, more than twice the height of Mount Everest-that runs three-fourths of the way around the moon. In addition, Iapetus itself is two colors, bright white on one side and dark brown on the other. Many of Saturn's larger moons have faint, wispy rings as well, trading particles with the rings of the planet.

Thanks to Cassini, we know the moons of Saturn more intimately than any other rocky worlds beyond the asteroid belt. These planetary bodies have liquids, they have water, they have atmospheres. The findings have shown that even hundreds of millions of miles from the warmth of a star, planets and moons can have active geology, flowing liquid, and abundant energy. Everything Cassini has shown us indicates that somewhere, lurking under the icy crust of Enceladus or swimming through the methane seas of Titan, there could even be life.

A Plane of Icy Particles

Saturn, of course, is most famous for its extensive ring system-an equatorial plane encircling the planet that is 30 feet wide at most, full of icy particles that range in size from micrometer specks (smaller than the width of a human hair) to boulders. With its many rings and moons, the Saturn system is a kind of micro-solar system to study, and the secrets of how it evolved could tell us something fundamental about how the whole solar system formed.

The Cassini team was surprised to find that, by and large, the ring particles of Saturn are not singular orbs floating around and occasionally crashing into each other as they circle the planet. The particles instead hit each other and clump together. Spilker, who specialized in studying the ring data from Cassini, says it looks a little like "parallel granola bars. We had hints of that in the optical data, too, because as you went around the ring, the brightness would change in a way that wasn't expected. But if you pop in the granola bar-it's called self gravity wakes-pop in that model, okay, everything works."

There are a few rogue objects floating around Saturn's ring plane as well that disrupt the typical swirl and cluster of small ring particles. Objects that are big enough to disturb the ring particles, leaving small spinning vortexes in their wakes as they fly along, are known as propellers.

Then there are the shepherd moons, including Pan and Daphnis, which are even bigger-large enough to clear miles-wide gaps. These small moons perturb the particles and produce some of the most captivating views of Saturn's rings-particularly Daphnis, the "wavemaker," which leaves cresting waves in its wake as it flies through the 26-mile-wide Keeler Gap in the A ring, sweeping it clear of debris.

One huge outstanding question is: How old is this dynamic ring system? Did Saturn recently rip apart a moon and distribute the particles across its rings? Or did they form along with the planet billions of years ago? We don't know-but Cassini has offered some new clues.

A recent study using Cassini data suggests the rings could be young, only about 100 million years old. During the final Cassini dives between Saturn and its rings, the craft got a good measurement of Saturn's mass without the rings. These measurements, obtained by studying the planet's magnetic field, can be subtracted from the total mass of Saturn and its rings to give you a mass for the rings alone.

After looking at these recent Cassini measurements, the science team believes the rings are in fact less massive than previous estimates, and therefore are likely comprised mainly of the remains of a ripped-apart space rock, or multiple. However, more than 99 percent of the material in Saturn's rings is water ice-not what you would expect to see if a rocky moon, even one with a lot of ice, were torn apart to create the rings. And the puzzle is always changing as the rings gain and lose material. (Saturn's E ring, for example is fed directly by the water vapor and ice ejected from Enceladus.)

One theory is that a moon-like object with a surface of icy crust got too close to Saturn, and the outer ice broke apart in the immense gravity to scatter across the rings, while the rocky core plunged into the planet itself and disappeared.

The eventual answer could have repercussions far beyond the sixth planet. The cosmic dance of icy particles around Saturn, coalescing into stable granola bars and them smashing apart in a flurry of chaos, could be the key to understanding how entire worlds formed during the formation of planets, moons, and asteroids in the solar system.

The Storm That Ate Itself

Saturn itself is even more elusive than its rings. We still don't really know how fast Saturn rotates, how deep down the winds penetrate the planet, whether it has a rocky core, or what Saturn is even made of in its gaseous depths.

"I didn't really expect how long the chain of surprises would last, and it still goes on," says Andrew Ingersoll, a professor of planetary science at Caltech who has been studying the atmospheres of giant planets for over 40 years. "Maybe I overestimated what we knew about astronomy and planetary science and atmospheric science and geology-all that, I said, 'oh well, we know so much just from studying the Earth, everything we are going to find out there. will just get tired after a while.' But it didn't work out that way."

During its 13-year stay, Cassini took measurements of the planet's atmosphere, magnetic field, gravitational forces, and radar signatures that will help us begin to peel back the layers of Saturn. Yet during Cassini's time at the planet, scientists were confronted with one baffling event after another.

It was a time of violent storms. One day, during a moment of mission down time, the spacecraft pointed its camera at Saturn to take a picture. "There was this little storm that had just begun that wasn't there the day before," Ingersoll says. Soon, that little storm grew into one of the largest and most volatile storms on Saturn that NASA has ever observed. A great tumbling mass of cloud and gas, wider than Earth, started high in the northern reaches of the ringed planet in December 2010. The storm encircled the entire gas giant, as if following a line of latitude. When the head collided with the tail about a year after the storm began, it faded out in the Saturnian haze.

These astronomic storms, sometimes called Great White Spots, occur about every three decades, or roughly once per Saturn year. Falling rain and hail within these deep storms generate electricity and spark cracks of lightning in Saturn's interior. These Great White Spots create an enormous amount of turbulence, with vertical winds that howl at 300 mph or more. Colossal pillars of cloud form similar to what you see during a thunderstorm on Earth, but the cloud pillars on Saturn stretch 10 to 20 times taller.

In February 2011, Cassini measured the storm with its visual and infrared mapping spectrometers. The team was surprised to find water ice and ammonia in the upper reaches of the clouds. The measurements gave scientists some hint of what lurks below the upper layers of Saturn's atmosphere, as material from deep within the planet was thrust to the surface during the violent lightning storm.

Why Saturn stores energy within and then releases it all at once during these periodic storms is still a mystery. The planet is unlike Earth and Jupiter in that way-both of which have multiple storms raging in their atmospheres at all times. Something about Saturn's structure and composition causes it to sit on stored energy, only to release it every three decades as a planet-encircling ring of chaos.

Saturn's summer solstice brought another surprise. The vortex at the north pole, a puzzling cyclone that somehow manages to maintain a hexagonal shape, baffled scientists yet again when it changed color. The north pole hexagon, which has been active at least since the Voyager flybys of Saturn almost 40 years ago, shifted from a bright blue in June 2013 to a faded tan, similar to the rest of Saturn's clouds, in April 2017.

The change in color has something to do with the increased amount of sunlight Saturn's north pole receives as the planet enters the summer season. Researches believe that the vortex, a six-sided jetstream, blocks hazy particles from entering the hexagon. When the storm is continually hit by direct sunlight, however, those smoky haze particles within the storm from a photochemical reaction in the atmosphere, returning the north polar hexagon to a soft golden hue that resembles the rest of the planet.

"Things we don't know [about the north polar hexagon]," says Ingersoll, "are: Why doesn't it run down? . Why doesn't it just slowly go away? The same is true of the long-lived storms like the Great Red Spot [on Jupiter]. . They're really enduring, and we don't know what keeps them going."

Future Exploration

Cassini has spent more than a decade beaming back breakthrough data and breathtaking images of Saturn and its moons, but after September 15, when the craft disappears into the atmosphere of Saturn, it will be some time before we return. The next two flagship NASA missions will be the Mars 2020 rover and the Europa Clipper to explore Jupiter's watery moon, similar to Enceladus but larger.

For anyone who worked on Cassini, the bottom line is clear: We need to go back. We need to go back to Enceladus to search for life. We need to go back to Titan to explore the alien surface. We need to go back to Saturn to fill in the history of the entire solar system.

While Enceladus and Titan have plenty of allure, Ingersoll has some broad advice when it comes to selecting a new mission to Saturn: Don't go to answer a single yes or no question, set yourself up for rich longterm exploration.

"One of my principles is, if you are going to go to a place, make sure you can collect a lot of data, make sure there are a lot of places where you can learn. that are capable of surprising you and are set up to make discoveries."

Beyond the Enceladus Life Finder headed by Spilker, there are a number of other mission proposals to return to the Saturn system. One, from the Johns Hopkins Applied Physics Laboratory, would attempt to send a quadcopter drone to fly through the thick haze of Titan. Another proposal within NASA would send a sturdy probe into the atmosphere of Saturn itself to more completely determine the composition of different layers of gas. In the coming months, we will find out which mission proposals receive a second round of funding and move on for further consideration.

Scientists will stay busy in the meantime with the treasure trove of data Cassini leaves behind. Additional discoveries about Saturn will come years from now, when a young scientist pulls up atmospheric data from Cassini and considers it with fresh eyes, or a visiting geologist glimpses something strange on one of the moons. The Cassini spacecraft will burn up, but its legacy will never die. It's like a great work of art, immortal as humanity.

"Yeah, it's going to come to an end," says Elachi. "But cheer up, this has accomplished amazing things, this mission, and it will probably be in the history books for centuries."

BY Draconis variable

Epsilon Eridani is classified as a BY Draconis variable because it has regions of higher magnetic activity that move into and out of the line of sight as it rotates. Observations have shown that Epsilon Eridani varies as much as 0.050 in V magnitude due to star-spots and other short-term magnetic activity. The reader should understand that [1] high levels of chromospheric activity, [2] strong magnetic field, and [3] the relatively fast rotation rate of Epsilon Eridani are characteristic of a pretty young star.

Because of this, the age of Epsilon Eridani is estimated to be about 440 million years, but this remains subject to debate. Most age estimation methods place it in the range from 200 million to 800 million years. Compared to our earth, this would place any planet in orbit around the star to be a rocky planet with a heavy and dense gaseous body swathed in vicious storms that shrouds a very hold, mostly molten planet surface. On the planet, particularly around the pole might be some early rocky continents with bleak mountains punctuated with volcanoes and extreme seismic activity. Not really a very hospitable place to live. The closest earth-similar geologic comparative would be the Hadean Eon.

In any event, this is a particularly young star and system. As such it is only marginally of interest towards habitability considerations. Of course, that doesn’t stop most people from looking up (on the internet) what the potential habitable zone would be around this star. (You can see one at Sol Station for Epsilon Eridani here.) It’s seems rather silly, doesn’t it?

I mean to say, yes in theory you can drive a road listed on a map near an active volcano. But, whether that road is clear and has a drivable surface is another issue altogether. The same is true with (potentially) habitable zones around really young stars. The data associated with the (so-called) zone of habitability is only appropriate in stable solar systems. It is not appropriate for young, growing, and immature solar systems.

The Epsilon Eridani system showing the observed dust and debris disks.

7 Answers 7

Estimates vary, but I'll be cautious and say that a radius of roughly two Earth radii is most likely the upper limit for rocky planets.

There are many studies, both theoretical and empirical, that have tried to attack the problem. I'll attempt to summarize the results of a few of them:

    : This group focused on planets losing their "hydrogen envelopes" - gaseous layers of hydrogen that they may accrete during the early parts of their lives. Their calculations indicate that planets of less than one Earth mass ( $M_$ ) would accumulate envelopes of masses between $2.5 imes 10^<16>$ and $1.5 imes 10^<23>$ kilograms. The latter is about one-tenth of Earth's mass. Planets with masses between $2M_$ and $5M_$ could accumulate envelopes with masses between $7.5 imes 10^<20>$ and $1.5 imes 10^<28>$ kilograms - substantially more massive than Earth! This is the peak envelope mass, though the group calculated that planets with masses of less than $1M_$ would lose their envelopes within about 100 million years. They found that planets with masses greater than $2M_$ will keep their envelopes, and so become "gas dwarfs" or "mini-Neptunes." : Lopez and Fortney worked off of data from Kepler and modeled the radii of planets. They determined that planets with radii of less than $1.5R_$ will become super-Earths, and planets with radii of greater than $2_$ will become mini-Neptunes. That suggests a radius limit of $2R_$ , though most terrestrial planets will probably be under $1.5R_$ . : This group tied mass and radius together based on theoretical calculations. They eventually came to the equation $M_s approx frac<4><3>pi R_s^3 left[1+ left(1-frac<3><5>n ight)left(frac<2><3>pi R_s^2 ight)^n ight]$ where $n$ is a certain given parameter and $M_s$ and $R_s$ are the mass and radius scaled by composition-dependent values. It is therefore possible to compare the papers by Lammer et. al. and Lopez and Fortney if $n$ is known. The resulting values are dependent on the material the planet is made of (see Table 3 for examples), but it seems that a pure silicate planet would have an upper limit of $3R_$ , while an ocean world could reach $4 ext<->5R_$ .

I'd go with about $2R_$ as the upper limit for terrestrial planets, though there may be exceptions in certain extenuating conditions.

That's for planets that form as terrestrial planets from the start. Curiously enough, gas planets can become terrestrial planets by having their outer layers blown away by their parent star, leaving behind an object called a chthonian planet. These "planets" aren't much more than the core of the gas planet. No chthonian planets have been confirmed to exist, but they're possible.

I should add that Samuel also proposed the $2M_$ -limit in his answer below.

Since we're talking about a planet, and not a star, we can compute the upper bound based on the maximum possible mass an object can have and still be made of atoms. The transition away from atoms being atom will take place when the force holding the atoms apart is overcome by the force of gravity. Once gravity is too great, our atoms will collapse into degenerate matter, forming a white dwarf.

The last opposing force, after the intermollecular forces forming the usual solid structure of an atom is electron degeneracy pressure. The amount of electron degeneracy pressure that exists is based on the average molecular weight per electron, which is $mu_e$ in this equation for the Chandrasekhar limit:

Ignoring everything else, all of which is constant with respect to the material the object is made of, we can see that the mass is inversely proportional to ($mu_e$).

Since the Chandrasekhar limit is about 1.39 for stars which have an iron core, which is to say that the core of the star will begin to degenerate when the star exceeds this mass, we can use the relative electron density of iron vs. our terrestrial element of choice to figure out how big our object can be. Silicon is about the best we can do, with 14 electrons and an atomic weight of 28. We may be able to do better with some lighter isotope, but then we'd have to worry about electron collapse stripping away too many of our electrons and collapsing our planet into a neutron star. Comparing this to iron, the core of most stars that we see going supernova (iron doesn't fuse and the stuff that does fuse is held apart by fusion pressures), which has an atomic number of 26 and an average atomic mass of 55.8, we can compute the effective mass per electron as 86.8% the electron, giving us a maximum mass for a silicon planet of 1.60 sols.

This planet, of course, would never form on its own. An object of this size would normally accumulate a thick enough atmosphere to undergo fusion, and would be a small star. Normal stars also don't produce nearly this much silicon unless they're really big, in which case they'll produce it and then rapidly fuse it into iron before going supernova. It is, however, assuming you can gather all that silicon up and put it in one spot without it gathering an atmosphere thick enough to push it over the edge mass-wise and turn it into a neutron star, the biggest ball of terrestrial elements one can possibly make. In other words, it is the theoretical maximum size for a rocky planet.

Why doesn't smashing larger and larger bodies incrementally into a rocky planet create a star? - Astronomy

The U.S Army marries Jupiter, the God of Gods.
NASA provides the Wedding Party.
A smashing orgasm!

An anonymous text posted on Newsgroups

(Jan, 28, 1997 on sci.astro)
about the comet Shoemaker-Levy 9

July 1994, the comet Shoemaker-Levy 9 crashed into the planet Jupiter. It was in March 1993, that astronomers discovered the strange celestial fairy made up of 24 aligned fragments traveling close to the biggest planet of our solar system. For over 15 months the scientific world observed the fragments, calculated with precision their collisions, and tried to imagine the effects and consequences of this encounter.

Right from the start with the very first impacts, the observers were greatly surprised, indeed astonished, by the extent of the "cosmic show." These "things" which exploded in the upper atmosphere of Jupiter from July 16 to 22, 1994, produced different visible or detectable effects such as giant fireballs, plumes that rose to an altitude of 3300 kilometers, debris fall-out which created gigantic dark stains reaching the enormity of FOUR TIMES THE SIZE OF THE EARTH, all this, as well as the effects in the infrared, ultraviolet, x-rays, and other observations less spectacular but by no means less important.

Scientists, having spent months dissecting all this information, haven't yet found explanations or models complete enough to include all the data.

It is a fact that this was the first time collisions such as these were witnessed in our solar system and, as the very day was predicted, a large number of observing and measuring instruments were pointed at Jupiter. The British review " Nature " reported: "Gene Shoemaker estimates that, on average, a 1.5-km-diameter comet is captured and tidally disrupted by Jupiter and strikes the planet once every 2,000 years. He added that for the impacts to happen as they did - after the repair of HST, when the Galileo spacecraft was suitably placed, during the era of very efficient infrared detectors, and while the United States government is still investing in basic research - was a miracle indeed." (1)

Seen from this point of view, it truly does look like a miracle. Yet miracles are rare, and they often have an explanation. Let us look at this one through another aspect of its reality: this cosmic event that we witnessed live, is nothing other than a large scale test of the latest superpower bombs of the U.S. military, launched into space by NASA and skillfully camouflaged as a cometary collision. Far-fetched? Not exactly. Let us explore this idea further.


To understand this, we must go back in time to the period when the Cold War was at its height, to the period when in the two "Superpower" countries, insane ideas were ripening, ideas of terrifying arms that would enable one country to take decisive advantage over the other. Very little time before, physicists had just conceived of and perfected the nuclear fission bomb in the dramatic context of World War II. August 1945, in Hiroshima and then in Nagasaki, humanity took a decisive step forward into the utilization of a colossal force of destruction.

This step forward kicked the door open in the United States, the Soviet Union, Great Britain, France and then in China to the development of the nuclear fission weapon, as well as the installation of its "big sister" of fusion: the H-bomb, known as thermonuclear. In the Sixties, while our world hadn't yet understood or even discovered the climactic phenomenon "nuclear winter" that would inexorably decimate the survivors of an atomic conflict and put an end to our earthly civilization, military laboratories were preparing the next step in great secrecy.

The U.S. military program, classified as the Defense Support Program 32 (DSP 32), explored a route totally different from that of particle accelerators, a route which allowed them to obtain a more ultimate form of energy: antimatter, ten thousand times more powerful than nuclear fission. Laboratories in the Western United States oriented their research towards very high densities within the framework of hydrogen fusion mastery. In their high density experiments, laser power is indicated by terawatts (a trillion watts), and pressure, by millions of atmospheres. The DSP 32 program also secretly worked towards a goal different from hydrogen fusion.

A certain number of physical parameters had to be pushed further in order to exceed the fantastic pressure of one hundred million atmospheres to reach the threshold where the balance of matter is broken, a threshold where some of its characteristics inverse: this is antimatter. In order to obtain this fateful pressure, a sophisticated technology is necessary the gigantic lasers at that time, even those of x-rays, weren't yet powerful enough. It was in reworking certain ideas of Andrei Sakharov, the Soviet Nobel Prize winner, that the first successes took place.

During the Fifties, Sakharov, known as the father of the Soviet H-bomb (before he became a militant for peace), perfected an electromagnetic cannon system which, in compressing a solenoid with the help of an explosive, enabled him to obtain a magnetic pressure of twenty-five million atmospheres, that which transformed a mini-charge of aluminum into plasma and ejected it at dizzying speeds of hundreds of kilometers per second. This system was therefore improved the standard solenoid was replaced by a solenoid supraconductor, and the conventional explosive, by a small atomic charge, facilitating the attainment of the necessary pressure threshold.

The target, instantly transformed into plasma, is ejected into a chimney where the particles of antimatter thus obtained, are sorted electromagnetically and gathered into a "magnetic bottle." LAURENCE LIVERMORE, SANDIA, LOS ALAMOS, NEVADA are among the many places which participated in this epic, each in its own way, sometimes under the cover of the experimental program: Centurion-Halite, the official program of research on the mastery of the fusion of hydrogen, but which also served as a cover when the experiments employed atomic explosives.

In the East the same research was actively and swiftly carried out, and if recently the technology suffered from a certain deficit, the ideas were often more advanced. During the decade of the Eighties, a little bald-headed man arrived at top of the government in Moscow. Conscious of the ultimate slope of world progress, he rapidly eased a great number of international tensions, efficiently restarted negotiations on disarmament, and actively cleaned house in his own country by scratching a certain number of advanced military research projects.

In the West, well hidden behind a shiny facade of peace defending, several "Doctor Strangeloves" were acting as ruthlessly as ever. Since their arms race had received a bullet in its wing, they learned to do without simply by thinking up a more diabolical ideas: experimenting with antimatter bombs on a large scale level, bombs which are thousands of times more powerful than any created up to this point. With the earth being too restricted geographically and strategically for this type of project, our "doctors" turned towards outer space and. the planet Jupiter.


It is obvious that such a project could neither be done in one day nor in broad daylight. For, on the one hand, the plan was to keep the technology secret, and on the other hand, according to the Space Laws (U.N. treaty of 1967, namely article 4), military experiments as well as the deployment of massive destructive arms into space are prohibited. But when the ambition to be masters of the world is strong enough, laws, even international ones, are just scarecrows to hide judiciously behind.

The realization of this project necessitated, therefore, a regrouping of a certain number of material elements, and the adoption of an ingenious and rigorous dissimulation strategy, both by technological contributions as well as by the preparation and manipulation of opinion. Let us look at some of these means.

August 16, 1984, the 175th Delta rocket, carrier of the Active Magnetospheric Particle Tracer Explorer (AMPTE) program, was launched from Cape Canaveral. The mission consisted of 3 small satellites which, over the course of one year, were first meant to release several "clouds" of barium and lithium at different points in intra and extra-magnetospheric space, and then to observe the evolution of the element tracer ions in order to study the interactions of solar wind with our magnetosphere. The material realization of this experiment was the result of the collaboration of several laboratories situated in three different countries (U.S.A., Federal Republic of Germany, United Kingdom of Britain).

The research goal of some was to study for an improved understanding of the earth's environment the unconfessed goal of others was to experiment in real conditions the creation of cometary phenomenon in order to observe its evolution over time as well as in diverse spatial conditions. Under the action of the sun's rays, the barium and lithium are rapidly ionized and have the characteristic of becoming fluorescent, creating, therefore, an artificial comet. The AMPTE program was one of the stages of preparation for the "Jupiter Project," one of the steps towards the perfection of the camouflage system by a cloud of particles of an alloy of barium-lithium.

"Then I came across this very strange-looking object. I thought it had to be a comet, but it was the strangest comet I had ever seen, (see below enclosed report)" (2) said Carolyn Shoemaker, recounting the night of March 24, 1993, at the Mont Palomar Observatory (California), where she was the first to observe the phenomenon which afterward would be called: the "periodic comet Shoemaker-Levy 9" or said more simply, "SL9."

Carolyn Shoemaker was no doubt far from imagining that she had just discovered the luminous barium-lithium clouds, those which were generated by the module-bombs.

The size of their clouds were adapted to the presumed force of the corresponding bomb. In certain cases the modules were grouped by two's and were able either to separate one from the other ("fragments" P and Q) or stay close together ("fragments" G and K), the latter which provoked explosions spaced apart by a few minutes where the phases were overlapping, the forces and epicenters slightly different in longitude, latitude or altitude.


The "SL9" modules were placed on a very eccentric jovian orbit over a 2-year period. This orbit, an oval shape stretched to the extreme, has the following characteristics: at one of its extremities (periastre), it passes at a distance from the mass center of Jupiter which is less than the radius of the planet itself, hence, it faces an unavoidable collision at the other extremity (apoastre), it brushes the limit of the gravitational attraction zone of Jupiter. If "SL9" had had a slightly faster speed, it would have left Jupiter's influence and continued its route on a solar orbit. In observing this trajectory, we rapidly notice that there is no better choice of orbital plan if one wishes to spend time far from Jupiter to have the greatest chance to be spotted and then to come back and strike the planet.

As far as the other parameters go, parameters which conditioned the impact sites, they were calculated so that the collisions took place on the back side of the planet, invisible from Earth. This was an indispensable precaution, as these explosions look exactly like nuclear explosions with powerful emissions of electromagnetic rays, primarily gamma rays, which would have fatally given away their questionable nature. However, even though no observer on Earth could directly see the events, moving in the obscurity of cold space at more than 11 kilometers per second, an eye was observing.

It was in 1973, the period just after the glorious Apollo missions that the Galileo project was born, even though it didn't take its real first breath until 1977. This program of advanced exploration of Jupiter and its environment, experienced a certain number of difficulties and several launch delays.

The departure finally took place October 8, 1989, and because its two-stage solid-fuel rocket was not powerful enough to take the direct route (a launcher restriction, due to the new security norms aboard the Space Shuttle), the spacecraft Galileo took the long way in order to benefit from several gravitational reactions (Venus and twice around Earth), finally reaching Jupiter in December 1995, at the end of a voyage of a record duration, more than 6 years.

Curiously, while the impacts of "SL9" were on the hidden side of Jupiter, slightly beyond the planet's limb, Galileo was at that moment in direct view of the event. Was it just by chance, or by judicious programming that Galileo was the only ocular testimony, looking innocently like a simple and fortunate coincidence? This spacecraft, loaded with cameras and multiple sophisticated detectors, was confronted right from the start with several technical problems: the large antenna, the registering tape, the probe parachute, etc. It is important to discern between the real technical problems and the strategic breakdowns which would offer an excellent pretext to occult a part of the information:=0B- delay of 50 seconds in the opening of the atmospheric probe's parachute which would mask the composition of the first kilometers of the jovien atmosphere, just at the altitude where the explosions seemed to have taken place.

momentary breakdown of recording devices which deprived us of close-up images of Io and Europe

programming error which hid certain data on the "SL9" impacts

As for the rest of the jovian mission, the possibility that the collected information be seriously skimmed and filtered before it was divulged, is more than just a simple hypothesis. Many scientists were astonished by certain gaps in information on the "SL9" observations. It is quite troubling that Galileo only filmed the relatively modest effects of the "SL9" impacts, when the astronomers based on Earth, even though they were five times farther away and not as well-placed, observed the grandiose effects which at times saturated the detectors.


Beyond the elements already cited here, a certain number of written communications and verbal interventions had for a goal to manipulate opinions in order to prepare minds and to provide channels of research with pre-orientated reflections. This ensured finally that the imaginations of the public and the scientific world didn't venture too far into prohibited zones. Here are some examples:

In the press there appeared a certain number of articles written by persons working at the laboratories directly implicated in the realization of these events. Of course these articles on "SL9" developed hypotheses, studies, and theories on the fragmentation, the evolution and the phenomena of the impacts of the "periodic comet captured by Jupiter."

Among the persons directly implicated in the program, there were certain who actively participated, like worms in the apple, at numerous scientific meetings pre- and post-impacts.

In 1993, the American Department of Energy was appointed to study ways of maintaining a safe stockpile of nuclear weapons in an era of "arms reduction." Hence, the Stockpile Stewardship and Management Program came into being. The tone of the program report exhibits a spirit of democracy, the respect of the international arms reduction agreements, the concern for national security, and the upheld ideal of "transparence." But as many people or groups imbibed with power use language to their advantage, the text manipulates lies perfectly to hide the reality. Throughout the report we can read that the U.S. no longer tests nor does it produce new weapons!


This project is not, strictly speaking, an element in the realization of "SL9." Its questionable goal is to open certain frightening possibilities for the future. This program which was submitted to the U.S Congress in 1992, was proposed under the theme of insuring the safety of our planet which faces the risk of a cosmic collision with asteroids and comets that might come too close to the earth's orbit. This project consists of the construction, the installation and the maintenance of 6 earth-based telescopes. Certain defenders of the program attempted to open the way to the utilization of nuclear weapons in space in order to destroy or deviate these hypothetical bolides.

Fortunately, the opinion of certain scientists was voiced in order to relativize the dangers, that is, the minor probability of a collision with the earth versus the major risk of the manipulation and the deployment of such weapons (either known or secret). One must note the particular way the presentation of the project was inscribed into a bigger scenario. The program, not being accepted the first time around, witnessed a revival of interest as the "collisions of SL9" hit the scene to incite new fears, permitting, therefore, its reconsideration, this time much more favorable.


This study would not be complete if we didn't look with hindsight on certain facts, namely, to ask the following questions:

Is this event the first and only experimentation of such bombs?

Given that this technology appeared in the Seventies, would the U.S. military have waited 20 years to test it?

The observation of a certain number of cosmic events prove that the answer is no. There is a specific category of comets which have the distinctive feature of grazing or even striking the sun.

This "Kreutz Group," as it is called, is made up of over 30 observations, the oldest dating from the year 371 B.C. What is interesting is that more than half of this group is composed of a wave of 16 mini-comets carrying the names of "SOLWIND" and "SMM," the two artificial satellites which observed them from a terrestrial orbit. This curious wave which took place from 1979 to 1989, is not without a strange similarity to "SL9," as all of them disintegrated in an explosive manner. The two military satellites were there, supposedly, to study the sun and its magnetic storms in reality, their more specific role was to observe the performance of these 16 experimental projectiles in their final phase.

The Kreutz Group comets which were spotted before had, for the most part, orbits inclined approximately 144 degrees. Therefore to insure the camouflage of these 16 bombs, it was necessary to have them approach the sun following the same incline. The 16 projectiles were not surrounded by a luminous halo of barium-lithium as was "SL9" thus, they were not visible in advance. It was only in their final phase of approach to the sun while they were plunging under the effect of the powerful solar gravity at speeds of 300 to 400 kilometers per second (or more than a million kilometers per hour), leaving behind them a luminous trail due to the heating up of the thermic shield, that they were able to be recorded by telescope-coronographs of the U.S. Military satellites. The strong luminosity of the solar disk obviously didn't permit a direct observation of the explosions only the illumination of the solar corona was observable by the coronographs during several hours after the impacts.


But all astronautic specialists will tell us: with the space launchers we have now, it is absolutely impossible to send a sizable payload towards the sun. This indeed would require an acceleration of over 50 kilometers per second, that is, much more than it took to send the spacecraft Galileo towards Jupiter. Galileo, weighing only 2200 Kg, couldn't benefit from a launcher adequate enough to provide the minimum acceleration necessary to leave directly towards its objective (6400 meters per second was needed, starting from the terrestrial orbit), and thus was restricted to take a long, complex route.

So how did they do it? Let us begin to answer this question by looking at a bit of elementary mathematics. It is of course the rocket engine thrust force that engenders the acceleration. The thrust is calculated by a very simple equation: it is the product of the ejection speed of the gas (at the propulsion-nozzle level) by the mass of the gas ejected, that is, the mass of the propergol withdrawn from the reservoirs. Since the beginning of the space era, propulsion technology has improved in dependability, but it has hardly evolved in performance, as it constantly runs up against the physical limit of the chemical combustion engine's gas ejection speeds which vary from 2.5 to 4.5 kilometers per second, according to the propergol used.

This limit restricts, therefore, the loading of enormous quantities of fuel used to augment the capacity of the launcher (2000 tons at liftoff for the Space Shuttle and close to 3000 tons for the Saturn V rocket) hence, a certain amount of research is done on other types of propulsors with heightened ejection speeds. These new propulsors allow for the diminution of fuel masses, and at the same time offer an augmentation in payload and performance.

In the field of space propulsion as well as antimatter (the two are in fact intimately linked), it is time to understand that we are faced with two realities, two levels of technology.

One, with mediocre performances, has been well-known for several decades

the other, with high performances, is kept an ultra-secret and is reserved for occulted military use.

During the Seventies, in the laboratories of Sandia (New Mexico), a new type of propulsor was perfected which, right from the first utilizations in space, accelerated ionized gas electromagnetically at close to 100 kilometers per second, indeed, a jump by a factor of 20 in comparison with performances of the best chemical combustion engines. In the standard technique, the propergol ensure both the supply of ejected material in the form of residual gas from the combustion, and the stock of energy in the form of an exothermic chemical reaction (combustion), which accelerates the gases. The new technology is, of course, very different and much more complex.

The material ejected, an isotope of silicon, doesn't undergo chemical modifications, rather, it is simply accelerated by powerful magnetic fields after having been vaporized and ionized. The source of energy of these propulsors is antimatter, itself which, by an astute autoregulatory system, produces the electricity necessary for the propulsion as well as for its proper confinement. Admittedly our study does not have the means to reveal the details of this top-secret knowledge.

All the same, it could be interesting to reflect on it, namely in remembering that the interaction of the gamma rays with a material produces powerful electromagnetic effects (effect EMP). That all this was thought up incognito and realized in an ultra-light system - a compact system perfectly adapted to spatial navigation - may seem incredible. Certain readers will be tempted to say impossible. However, the wisdom of science doesn't ask us to believe in the existence of things, not more than it obliges us to believe in their non-existence. It pushes us to study, to verify it urges us to open our eyes.


In order to stay undercover, this new technology was obviously not used in the first phase of launching, that is, the phase which went from lift-off to satellization in an terrestrial orbit. For this step standard launchers were used, principally the Space Shuttle and its classified military missions.


The experiments with the sun began in the advent of the Space Shuttle therefore, it was the launcher TITAN that was used. TITAN rockets, which are for the most part reserved for military usage, had already at that time in the version III, and then 34D, a capacity to put 14 to 18 tons into a low terrestrial orbit. For the missions to the sun, the TITAN rocket put into orbit a payload containing one module-bomb which was placed inside the last stage of the rocket. It is this stage, equipped with an antimatter propulsor, that insured the departure from the earth orbit towards its objective. Over the course of the 1980's, it was the Space Shuttle that was most often used (but not exclusively). The first three military missions - January 24, 1985, October 3, 1985 and December 2, 1988 - had this destination.

There was one additional mission that had the same target: the second test flight of Columbia, November 12, 1981. It is true that it wouldn't have been "clean" to put a military mission right at the start of the Shuttle program it was much easier, therefore, to place it discreetly into one of the four test flights. The November 12th mission of Columbia holds the record for the heaviest take-off weight of all the unclassified shuttle launches, hence, it was necessary to conciliate its covered-up objective with the material needed for the announced objective, that is to test fly the Space Shuttle.

During these missions, the same rocket stage that was previously used with the Titan launchers, was placed in the Shuttle's payload bay. However, this time it contained not one, but two module-bombs, as the Shuttle's payload capacity is 30 tons, which is double that of Titan rockets. In astronautics, when high-performance equipment is available and the amount of time to fulfill an objective isn't restricted, there are often a whole range of trajectory possibilities. If also the goal is not to be spotted, the voyage routes and times need to be varied. Hence, there are no correlations between the launch dates and the observations of the SOLWIND and SMM comets.

Nevertheless, there is a common element in the chosen trajectories: a passage by the outskirts of the planet Mercury. Of course it was not a direct meeting which would have been too visible for certain observers, but rather a deferred encounter, a bit like the spacecraft Magellan, launched in 1989, which reached Venus after a journey of 15 months and one and a half orbits around the sun. It is interesting in this optic to observe the reciprocal positions of Earth and Mercury at the time of each mission: November 12, 1981 and January 24, 1985, on the one hand, as well as October 3, 1985 and December 2, 1988, on the other.

Having reached a certain point of the voyage, the module-bomb left the stage rocket where it was housed. The module which had a short cylindrical form like a large tuna can, was equipped with a small propulsor, the nozzle placed on the circle's circumference, allowing it to move laterally. The module once liberated, traveled towards its final objective: the Sun. If two modules were aboard the stage rocket, the second one stayed an additional amount of time inside its carrying vessel in a "parking" orbit before taking flight.

Operation "SL9" was obviously a much bigger project. It was made up of 6 military missions of the Space Shuttle which were reserved for this event. Their departures from Cape Canaveral were spread over 3 years,

  • beginning August 8, 1989 (Columbia),

  • followed by November 22, 1989 (Discovery),

  • February 28, 1990 (Atlantis),

  • November 15, 1990 (Atlantis),

  • April 28, 1991 (Discovery)

  • and finally November 24, 1991 (Atlantis).

Each Shuttle carried in its payload bay a long cylindrical cargo spacecraft equipped with a large propulsor in the back. Since the first launches towards the sun, 10 years had passed, and the technology had greatly miniaturized, allowing for a greater number of bombs to be carried at each mission. The 6 cargo vessels didn't all have the same size: 4 of the vessels contained 3 module-bombs each the 2 others, being much larger held 6.

This means there were a total of 24 bombs. The smaller vessels were conceived to ensure that if problems occurred with the Shuttle fleet, the vessel could be launched by the TITAN IV. Each cargo vessel individually took the route to Jupiter, following a trajectory adapted according to the position of the earth at the moment of the launch and the time it had to reach its destination.

It is important to remember that the "comet SL9" was discovered March 23, 1993 however, in examining older snapshots, it was also photographed March 15, 1993. But curiously before this date, nothing had been observed even though this "SL9" was supposed to have fragmented in proximity to Jupiter in July 1992, and also was supposed to have traveled on this orbit with its dust clouds for 8 months, having theoretically journeyed more than 40 million kilometers.

It must be made clear that this space convoy never passed in proximity to Jupiter in July 1992, but rather around March 1, 1993, it directly joined a point in this jovian orbit very close to where it was discovered. Thus, the last cargo vessel which left Earth November 24, 1991, made the trip to Jupiter in hardly more than 15 months. At the departure from the earth's orbit, it had to create an additional acceleration of about 8400 meters per second, then in arriving at its objective it needed to accelerate again (actually a breaking) this time around 15,000 meters per second.

If we want to compare the performances of the two types of space propulsion, we must note that in 1979, one of the space probes "Voyager" realized the trip Earth-Jupiter in almost the same time (18 months), but only the first acceleration at the departure was necessary. For in passing the neighborhood of Jupiter, the spacecraft maintained its speed in order to continue its route towards Saturn. What's more, Voyager was actually a feather (800 kg) next to the cargo vessels of "SL9" which weighed 15 to 30 tons.


After voyaging solo, the 6 cargo vessels met at around 40 million kilometers from Jupiter. There they were aligned on the known orbit of "SL9", the payload doors were opened and the module-bombs were mechanically ejected. Once their cargo was discharged, the vessels fell away from the trajectory and auto-destructed by explosion.

The fine positioning of each module-bomb on the jovian orbit was achieved by trajectory corrections with the aid of a small propulsor engine. Once on the orbit, the camouflage system was activated: the barium-lithium was heated, liquefied, then vaporized out of the module. In cold space it resolidified into very small particles which the sun's rays rapidly ionized. A powerful magnetic field outside the module, created by antimatter energy and supraconductor technology, was put into effect which trapped and conserved most of the ionized particle cloud. In the jovian approach phase, when the modules crossed into the magnetosphere of the planet, the interaction of the two magnetic fields made the modules progressively lose the outer layer of the particle cloud leaving only the central core, the densest part, closest to the bombs.

At the entry into the jovien atmosphere, it was, therefore, the core of ionized particles which collided with the molecules of the outer layer of the planet's atmosphere and provoked the first luminosity which in certain cases was observable from Earth, above the limb, above the horizon of Jupiter. (click image right to enlarge and watch Video)

These 24 modules, even though globally conceived around the same principle, differed in size, explosive power and technology. It was the module/"fragment" K which evoked the strongest interaction with the planet's magnetosphere, creating powerful particle accelerations of ions and electrons, found there. These particles which traveled rapidly along the lines of the jovian magnetic field, produced x-ray emissions in Jupiter's atmosphere even before the impact.

We remember that in December 1995, Galileo's probe plunged into the jovian atmosphere with a relative speed nearly equal to that of "SL9" (50 kilometers per second, Galileo 60 kilometers per second, "SL9").

The probe was equipped with a highly efficient thermic shield made to resist the intense heat provoked by its entry into the atmosphere the "SL9" modules didn't use this sort of thermic shield. It would be very interesting if the promoters of this operation explained the technology that was used at this precise moment of the mission, given the fundamental importance of this knowledge. When this information is in better hands at the service of nobler objectives, Man's voice from the moon can once again proclaim: "One giant leap for mankind."


It was hardly more than a century after the famous novel of Jules Verne, "From Earth to the Moon," that two men walked on the lunar soil for the first time. At the memory of the glorious expedition of Apollo XI, the world still pulses with emotion. This great event was lived by the majority of people as a true advance of human civilization which, beyond the technological exploit, made us aware that humankind is not irremediably attached to planet Earth, thus opening the way one day to voyage further in the universe. The famous words spoken by Neil Armstrong on this occasion symbolized the immense hope of peace and world cooperation that was placed in the space program. Without a doubt this noble et legitimate hope is only one more illusion that we must confront.

Even at the time, certain clues should have inspired doubts: the "race to the Moon" was in fact completely inscribed in a political challenge, the West against the East, capitalism versus communism. The flag planted in the lunar soil was not a global symbol or even the emblem of the United Nations. The Stars and Stripes represented a U.S. political victory. But why talk about the conquest of the Moon? What

does it have to do with the story of "SL9"? Well, looking closely we find an interesting parallel:

The enormous Saturn V rocket, carrier of the Apollo XI mission took off on July 16, 1969. Neil Armstrong and Edwin Aldrin aboard the lunar module stayed on the Moon July 21st and, after having joined Michael Collins, left the lunar suburbs July 22.

The first impact of "SL9" took place July 16, 1994 the bombardment of Jupiter continued until July 22.

By this very particular manner of celebrating the 25th anniversary of Apollo XI, the American military-spatial lobby shows us its real objectives when it comes to the mastery and the utilization of space.

It is undeniable and fortunate that space launches have improved in reliability since their beginning. It is nevertheless true that tragic accidents still happen, because in fact no technology is absolutely sheltered from accident. We remember in 1996, the spectacular failure of the first test launch of the European Ariane V, a rocket designed with the idea of dependability. Also in 1996, there was the tragic accident of the Chinese rocket which took the lives of many innocent victims. But it is certainly the Space Shuttle Challenger disaster on January 28, 1986, which marked the memory of those in the Western world. That day, the 25th Shuttle flight, Challenger and the seven crew members were lost in a violent explosion under the aghast gaze of millions of onlookers and television spectators. In the instants that followed, the smoke trails left a swan in the sky.

We have seen that numerous times Titan rockets and Space Shuttle have transported superpower antimatter bombs as well as military engines functioning with this energy. Who would dare imagine what would have happened if one of the flights had witnessed a fatal failure?

During the course of the 1980's several teams of scientists carried out rigorous studies on the consequences of a nuclear conflict. (3) The climactic modifications which the explosions would have engendered from such an event would have had as consequences, in very little time, besides the countless victims directly hit, the disintegration of our civilization, if not the pure and simple extinction of humanity as well as the major part of the plant and animal kingdoms. Each one of us can form a personal idea of the risks taken by the fabrication and the manipulation of antimatter.

For it is important to understand that contrary to the nuclear bomb that only explodes when one activates the firing system, antimatter, once created, MUST BE CONFINED ACTIVELY AND PERMANENTLY by magnetic fields in order to keep it from entering into contact with matter in which case it explodes. One must also know that each one of the bombs fabricated, possesses a force equal and often superior to the entire world-wide nuclear power!

What would happen if an incident occurred during a manipulation over the Western American states or if a Space Shuttle or another bomb-carrying rocket had an accident? Right from the beginning minutes, all life on the North American continent would be annihilated by an enormous fireball that would cover several thousands of kilometers. Then would come the shock wave, the intense heat and the electromagnetic waves that would continue their devastating effects over a much vaster area. Finally the phenomenon "nuclear winter" would spread rapidly over the totality of the planet, and Earth would lose herself in an almost total obscurity and a glacial cold.

One can read in diverse literature and even in the Bible, of dark prophecies of an apocalypse for a period which highly resembles ours. Yet nothing is ineluctable. But are we willing to see are we willing to accept our responsibilities will we have the courage to say NO to destructive insanity?

Mister President of our beautiful France, will your little firecracker of the Southern Islands finally be ready? Will it at last be perfected in order to give to the day of the big saga, a modest but 100 percent French touch, bringing in "a certain image of France," an image dear to the heart of the French? By the events of Mururoa (Tahiti), you knew with authority how to get yourself recognized by the whole world that subtitle and last little touch could perhaps in the future allow you to inscribe for good your name (in small letters at the end of the list) in the cold gloom of posterity.

At the term of this study, many will be the assiduous observers of spatial activity, who, after having added everything up, will ask the question: "But the last military mission of the Space Shuttle (December 2, 1992), where did it go?" If we had the means we could of course cover every planet in the solar system with "wanted" posters. Since that possibility is not feasible, we are, therefore, constrained to work our brains in an attempt to discover a logic behind the destination.

We have seen that the first 16 bombs left for the sun and exploded in or at the approach to the solar corona the intense luminosity of the sun hardly permitted a precise observation of the effects. The sun, at least in its periphery, is a hot and gaseous star. The next 24 bombs went towards Jupiter, and the observations of the effects this time were clearly much easier. Jupiter is a cold and gaseous planet. It seems logical, therefore, to think that our investigators would have had the desire and the curiosity to experiment with their bombs on a planet not gaseous, but telluric, that is, a rocky planet like Earth or the Moon. The planet of course must be relatively far from the earth which excludes a priori: the Moon, Mars, Venus and Mercury.

It is also necessary that there be a way to observe the explosions, that is, to have an on-site observer. At the moment it is the satellites of Jupiter which correspond to these conditions, with the spacecraft Galileo which is in place for a close observation. What's more, if we put this deduction next to the curious breakdown of Galileo's recorder when it passed Io and Europa in December 1995 - a breakdown which officially deprived us of close-up images of these two satellites, images which perhaps wouldn't be judicious if we compared them with other images in the future - one could reasonably be frightened for one or the other of the jovian satellites.

According to the laws of astronomy about every 13 months, the system of Jupiter is found diametrically opposed to the earth, in relation to the sun. This means for an observer based on Earth, the solar luminosity inhibits all observation of the giant planet and its satellites. In 1997, this conjunction takes place the end of January. Wouldn't these be ideal conditions for camouflage? For a couple of years we have witnessed a media campaign to heighten public awareness on the observation and study of impact craters and chains of craters on different bodies in the solar system scientific interest or ultimate strategy of mind preparation? In a couple of weeks Jupiter and its satellites will once again be observable. Astronomer friends grab your telescopes!

Destructive insanity, which includes power and hate, fear and terror, is brought to its height in a certain number of individuals or groups of individuals around the world. It is also true that a great number of aspects of this insanity are more or less present in each one of us, just as it is true that the desire for peace, the desire for sharing, the desire for harmonious balance (do we dare say the seeds of love), are also present in each one of us. To position oneself in one or the other of these directions is a choice entirely personal and individual. At the planet level the sum of the all the individual choices is none other than the collective conscious of Humanity and. ITS DESTINY.

Kepler 22b: Why it is Almost Certainly NOT Habitable by Rich Deem

NASA has made an announcement of finding the first "earth-like" planet in the middle of the star's habitable zone through the Kepler satellite, which finds planets through stellar dimming during transits. To date (2011), over 700 extrasolar planets have been confirmed to exist, although Kepler has a potential list of over 2,000 more. The current announcement probably had the widest news coverage of any recent NASA statement. This page examines the claims, along with distortions by the media, and NASA artists themselves.

Parent star

Stars and planets are given names according to the following convention. A star's name usually includes some numbers identifying it. The planets being discovered by the Kepler mission are being numbered sequentially by discovery. Stars are labeled with the number followed by the letter "a." So, the "name" of the star around which the new earth-like planet is revolving is designated as Kepler 22a. 1 Planets are numbered with subsequent letters, beginning with "b." So, the newly discovered planet is designated as Kepler 22b. Unlike the last announcement of the last "earth-like planet," Gliese 581g, within its small star's habitable zone, this one is orbiting a near solar-twin. Small stars, like Gliese 581a, exhibit lower energy spectral emissions, which are not conducive as strong supporters of photosynthesis. In addition, their weak emissions require planets to be located very close to the parent star to be within the habitable zone, resulting in tidal locking (one side of the planet always faces the star). Stars larger than the Sun burn much more quickly, with rapid escalation of stellar luminosity, which continually moves the habitable zone further and further away from the star. So, realistically, only stars that are nearly solar twins would be conducive to harboring life. Kepler 22a happens to be such a star, which is why scientists were so excited to find a rocky planet orbiting around it.

Habitable zone

NASA's definition of the habitable zone is very generous. For example, using our own solar system, they say that Venus and Mars are both within the habitable zone. However, according to the inverse square law, the solar irradiance received by Venus should be nearly twice that of earth. Even with Earth's relatively thin atmosphere, it would be uninhabitable, due to overheating, if located as close as the orbit of Venus. However, since Venus has a thick greenhouse atmosphere, surface temperatures are in excess of 460°C&mdasheven higher than Mercury, the closest planet to the Sun. If the earth were located toward the outer limits of the Sun's habitable zone, beyond the orbit of Mars, it would a frozen ball of ice. Planet Kepler 22b is located near the inner part of Kepler 22a's habitable zone, so it's likely to be much warmer than the claimed 72°F in news stories. 2

Planet Kepler 22b

Although declared to be "earth-like," Kepler 22b is actually 2.4 times more massive than earth. This increased mass likely impacts the atmospheric content of the planet. Planets must possess a minimal mass in order to retain an atmosphere. For example, Mars has only 10% the mass of the earth, and almost no atmosphere. Extensive evidence indicates that it once had a thicker atmosphere and large bodies of water on its surface. However, because of its reduced gravity, it lost nearly all of that atmosphere and water due to the actions of the solar wind. The earth originally had a much denser atmosphere that was mostly blasted into space during the collision that formed the Moon. Had it not been for this fortuitous collision, the earth would have had an atmosphere similar to Venus (81% the mass of the earth), which has an atmosphere 80 times denser than earth's. NASA scientists have assumed that Kepler 22b has an atmosphere similar to earth's. This assumption is almost certainly wrong, unless the planet experienced a large collision event, similar to earth's, early in its history. With at least 2.5 times the mass of earth, the planet would likely have an atmosphere much denser than Venus, making life there extremely unlikely. Such a dense atmosphere would contribute to a large greenhouse effect, which would raise temperatures dramatically. If Kepler 22b ever had water, it probably doesn't now, having been evaporated and blown away by Kepler 22a's solar wind. The artist's impression (right) is almost certainly wrong, since even NASA scientists admitted in their December 20, 2011 news conference that Kepler 22b most likely has a very dense atmosphere compared to earth (not the thin, wispy clouds we see in the diagram).


The newly confirmed planet Keppler 22b has been advertised as being an earth-sized planet within the habitable zone of its star, with an average temperature of 72F. What the new media does not tell you is that the temperature assumptions are based upon the planet having an atmosphere identical to earth's. The assumption is extremely unlikely. First, the earth's atmosphere is very thin for the size of planet, having achieved such a thin atmosphere due to the collision that formed earth's moon. Since Kelper 22b is 2.4 times more massive than earth, it most likely has an atmosphere as dense or denser than Venus. With such a thick atmosphere, any water on the planet would be in the form of superheated steam or boiled off completely. I wouldn't plan on moving there any time soon. If you do, remember to take lots of sunblock!

Related Resources

Rare Earth: Why Complex Life is Uncommon in the Universe by Peter D. Ward and Donald Brownlee

A secular book that recognizes the improbable design of the earth. Paleontologist Peter D. Ward and astrobiologist Donald Brownlee examine the unusual characteristics of our galaxy, solar system, star, and Earth and conclude that ET may have no home to go to. Surprisingly, the authors conclude that the amazing "coincidences" are the result of good luck and chance.

A classic book for modern Christian apologetics and science, recently updated with fully one third of the book updated. Dr. Ross presents the latest scientific evidence for intelligent design of our world and an easy to understand introduction to modern cosmology. This is a great book to give agnostics, who have an interest in cosmology and astronomy.