All,
Thought it would be appropriate to post the below articles on all the recent discoveries/ revelations being made about the possibility of life existing on some of the Moon's of Saturn, these discoveries occurring while the transiting Pluto, organic life, have been moving across the S.Node of Saturn.
God Bless, Rad
**************************************************************************
Hidden Ocean Found on Saturn's Icy Moon Enceladus, Could Potentially Support Life
By Mike Wall, Senior Writer | April 03, 2014 02:01pm ET
The Saturn moon Enceladus harbors a big ocean of liquid water beneath its icy crust that may be capable of supporting life as we know it, a new study reports.
The water ocean on Enceladus is about 6 miles (10 kilometers) deep and lies beneath a shell of ice 19 to 25 miles (30 to 40 km) thick, researchers said. Further, it's in direct contact with a rocky seafloor, theoretically making possible all kinds of complex chemical reactions - such as, perhaps, the kind that led to the rise of life on Earth.
"The main implication is that there are potentially habitable environments in the solar system in places which are completely unexpected," study lead author Luciano Iess said in a video about the discovery produced by his home institution, Sapienza University in Rome. "Enceladus has a surface temperature of about minus 180 degrees Celsius [minus 292 degrees Fahrenheit], but under that surface there is liquid water."
The new finding, which is published online today (April 3) in the journal Science, doesn't exactly come out of left field. Rather, it confirms suspicions many researchers have had about Enceladus since 2005, when NASA's Cassini spacecraft first spotted ice and water vapor spewing from fractures near the moon's south pole.
Cartoon illustrating the possible interior of Enceladus based on Cassini gravity investigation, which suggests an ice outer shell and a low density, rocky core with a regional water ocean sandwiched in between at high southern latitudes. Cassini ISS images were used to depict the surface geology and the plumes.
Measuring Enceladus' gravity
Iess and his colleagues mapped out Enceladus' gravity by measuring how the 313-mile-wide (504 km) moon tugged on Cassini during three close flybys from 2010 to 2012.
"As the spacecraft flies by Enceladus, its velocity is perturbed by an amount that depends on variations in the gravity field that we're trying to measure," co-author Sami Asmar, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. "We see the change in velocity as a change in radio frequency, received at our ground stations here all the way across the solar system."
This ultra-precise tracking system - NASA's Deep Space Network can tell if Cassini speeds up or slows down by just 1 foot (0.3 meters) per hour - revealed the presence of a "negative mass anomaly" at Enceladus' south pole. In other words, the area harbors less mass than would be expected for a perfectly spherical body.
That makes sense, because a large depression marks the south pole's surface,researchers said. But the observed mass anomaly is significantly smaller than expected based on the size of the dent (about 0.6 miles, or 1 km deep).
The researchers thus concluded that "extra" mass underground must be reducing the effect. A subsurface ocean of liquid water, which is denser than ice, is the only reasonable candidate, they said.
The heat required to keep this water in a liquid state is generated within Enceladus, with much of that energy perhaps coming from tidal interactions between Enceladus and another of Saturn's moons, Dione. The moon's internal energy stores are prodigious; a 2011 study found that Enceladus' south polar region pumps out 15.8 gigawatts of heat-generated power, equivalent to the output of 20 coal-fired power plants.
A lot of water
The team's calculations suggest that the moon's ocean covers at least as much area as Lake Superior, the second-largest lake on Earth - though the icy moon's sea is much deeper than Lake Superior and thus holds a great deal more water.
The ocean is likely confined to the moon's southern hemisphere, reaching halfway to the equator or so from the pole. But the study team cannot rule out the possibility that it extends globally, said co-author Dave Stevenson of the California Institute of Technology in Pasadena.
The subsurface sea probably feeds Enceladus' geysers, which blast organic compounds - the carbon-containing building blocks of life as we know it - into space along with ice and water vapor.
Further, the new study marks the first time scientists have used gravity measurements to discover an ocean on another world, Stevenson said. For example, researchers inferred the existence of a subsurface sea on Jupiter's moon Europa from magnetic-field data, which indicated the presence of an underground conductive layer (almost certainly salty water).
Water on rock
The gravity measurements also suggest that Enceladus is composed of layers of different materials, with a low-density core consisting of silicate rock underlying the ocean, researchers said. This is good news for anyone hoping that life may have sprung up on the frigid Saturn satellite.
"When you have a situation like this, where the ocean is sitting next to the rock, there's a greater likelihood of some interesting chemistry," Stevenson said.
Europa's sea similarly abuts rock, while some other satellites - such as Jupiter's huge moon Ganymede - appear to have subsurface seas that touch only ice above and below, he added. Indeed, the similarities between Europa and Enceladus continue to mount. Late last year, for example, researchers announced the discovery of water-vapor plumes erupting from Europa's south polar region.
Click to watch: https://www.youtube.com/watch?v=Jvk8WP80Ivw
*************************************************************************
Is Life Possible On Saturn's "˜Death Star' Moon?
Could Saturn's "Death Star" moon show some signs of life? A new theory has been proposed about the Death Star moon in the scientific journal Science about one of Saturn's moons. Based a new model of the Death Star moon, it could be showing signs of a possible life-sustaining ocean under an icy crust.
The team of researchers, led by planetary scientist Radwan Tajeddine from Cornell University, used the data and images collected by NASA"˜s Cassini spacecraft to develop a 3-D model of the Death Star moon and its rotation, and learned that the moon had more of a wobble to it than what was expected. "The amount of wobble we measured is double what was predicted", said Tajeddine.
Two possible theories have been presented to explain these findings. The first is that laying beneath the moon's icy surface is a liquid ocean which is giving Saturn's Death Star moon its wobble. While this seems like the most likely explanation, some are skeptical because there does not appear to be any geological indications on the surface of Saturn's moon to support this particular hypothesis. However, depending upon just how thick the ice layer of the Death Star moon is, it is still possible that we would not be able to to see any indications on the surface at this point.
Given the recent discovery of life brimming a half of a mile under the frozen surface of the Antarctic on our own planet, the possible existence of an ocean beneath the frozen surface of the Death Star moon raises some exciting possibilities for the existence of life outside of our own planet.
The second possible explanation for the wobble of Saturn's Death Star moon is that, for some unknown reason, the core of the moon was frozen somewhat rapidly into a cone-like shape, throwing off the otherwise spherical shape of the Death Star moon. The problem with this hypothesis, however, is that Saturn's moon formed over 4 million years ago, and after that much time the general laws of physics tells us that the core should have developed into a roughly spherical shape by now. Either way, it is clear that, as Tajeddine stated, "this cratered little moon may be more complex than we thought."
Saturn, as well as Jupiter, has other watery moons including Saturn's Titan, and Enceladus, and Jupiter's Europa. It is believed that the constant push and pull of the gravity of Saturn during the Death Star moon's elliptical orbit generates tidal energy that could provide enough heat for a flowing sub-surface ocean similar to what scientists believe may be found under the icy surface of Europa.
Saturn's Death Star moon, called Mimas, got its nickname because it is a bit of a dead ringer to the Death Star space station used in the Star Wars series that was used to destroy Princess Leia's home planet of Alderaan. How ironic that the Death Star moon, named for something so destructive, could offer new clues for extra-terrestrial life. More research is needed in order to make any solid conclusions about what is lying beneath the surface of the Death Star moon but the new data is certainly offering some exciting new possibilities.
*************************************************************************
Life on Saturn moon? Discovery of hidden ocean on Titan tantalizes.
Scientists already knew Titan has the building blocks for organic life in abundance. Now, the discovery of a underground sea with liquid water adds another intriguing element.
By Pete Spotts, Staff writer June 28, 2012
NASA/AP/File
A global ocean appears to lurk miles beneath the surface of Saturn's moon Titan, adding to the allure of an object rich with the building blocks of organic life and often likened to Earth before life emerged.
Cassini has already found large lakes - most likely made of hydrocarbons such as liquid methane - on Titan's surface. But a team of scientists using NASA's Cassini spacecraft have now found indirect but telltale signs of a subsurface sea, perhaps of water as well as ammonia, which would act like antifreeze.
The data suggest that the ocean, perhaps more than 15 miles deep, is sandwiched between two layers of ice, each less than 60 miles (100 kilometers) thick. It rides atop one layer of ice covering the moon's rocky core and appears to be capped with another ice layer that forms Titan's surface.
Titan has captured the imagination of scientists hunting for potential habitats for simple forms of life for decades. The temperature at Titan's surface is unbearably cold, minus 290 degrees Fahrenheit. It is paved with the methane ices and other organic solids on which Cassini's Huygens probe landed on Jan. 14, 2005. Its atmosphere is thought to mirror the composition of Earth's atmosphere before the emergence of life some 3.8 billion years ago.
As hostile as the surface seems to be, "liquids from below would enhance the possibility of life being on the surface" as well as enhancing the possibility of aquatic habitats deep beneath Titan's crust, says Dirk Schulze-Makuch, an astrobiologist at Washington State University in Pullman with a keen interest in Titan's potential habitability.
Thursday's report represents "a nice step forward" in establishing an ocean's presence on Titan, he says.
The new finding adds Titan to the growing list of moons thought to have subsurface oceans. The icy surface of Jupiter's Europa is believed to hide a vast ocean, and data from Cassini suggest a large, if not global, region of water or slush under the icy sheath of Saturn's Enceladus. Neptune's moon Triton may also have a subsurface ocean, and Ganymede and Callisto, two more Jovian moons, also are though to have under-ice seas.
But Titan stands out because researchers know that organic compounds are abundant there.
Researchers led by Luciano Iess, a scientist at the Universita La Sepienza in Rome, used radio signals from Cassini to track changes in the effect Titan's gravity has on the orbiter during flybys. These readings allow the team to measure the strength of Titan's gravity in the regions Cassini overflies.
This process allows researchers to "weigh the moon, basically," says Sami Asmar, a scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and a member of the team that reported its results on Sciencexpress, the web outlet of the journal Science.
If Titan was solid, its gravity field wouldn't change. Even when the moon comes closest to Saturn on its elliptical orbit - experiencing Saturn's strongest tug - its mass would remain fairly evenly distributed throughout the object.
But Titan's gravity changes as it progresses along its orbit, the team found. The side of the moon that always faces Saturn bulged as Titan made its closest approach to the ringed planet.
"We caught Titan in the act of deforming," Dr. Asmar says.
This tidal bulge represents a redistribution of material within the moon's interior - a telltale sign that there is likely a fluid layer in the moon's interior. It is as though Titan's rocky core with its icy cover was being drawn through the global subsurface ocean toward Jupiter as the moon made its closest approach, creating the bulge.
The friction of the moon's tidal interaction with Saturn generates heat, which could help sustain the ocean's liquid state - as is the case within Enceladus and Europa. The observation of a global ocean beneath Titan's icy exterior is indirect, Asmar says, "But it's real evidence."
*************************************************************************
How Titan might be making DNA building blocks
Saturn's moon Titan has many of the components for life - but no liquid water. A new study shows how the moon's atmosphere might be producing the molecules that make up DNA anyway.
By Pete Spotts, Staff writer October 8, 2010
Chemical reactions in the orange atmospheric haze that surrounds Titan could be creating the molecules that make up DNA, according to a new study. The orange hydrocarbon haze that shrouds Saturn's frosty moon Titan could be creating the molecules that make up DNA without the help of water - an ingredient widely thought to be necessary for the molecules' formation. What's more, it could be doing this with help from an unexpected source: another moon of Saturn some 610,000 miles away. Just because Titan's atmosphere is creating these molecules doesn't mean that the molecules are combining to form life, caution the researchers from the US and France who conducted the experiments. But the results could prompt astrobiologists to consider a wider range of extrasolar planets as potential hosts for at least simple forms of organic life, the team of scientists from the US and France suggests.
Moreover, the results could offer greater insight into how life on Earth formed. Although Titan is far colder than the early Earth would have been, the makeup of its atmosphere is thought to be comparable to that of Earth's billions of years ago. The new findings suggest that on the early Earth, the planet's upper atmosphere - not just the so-called primordial soup on the surface - may have been the sources for these "prebiotic" molecules, amino acids and the so-called nucleotide bases that make up DNA.
"We're really starting to get a sense for what kind of chemistry an atmosphere is capable of" performing, says Sarah Hörst, a graduate student in planetary science at the University of Arizona, who led the research effort.
Titan's mystery molecules
The inspiration for the experiments came from NASA's Cassini spacecraft, which has detected large molecules at altitudes of some 600 miles above Titan's surface. But the molecules are so far unidentified because of limitations to the craft's instruments. Lab instruments back on Earth, however, have no such limitations, so the team decided to replicate Titan's atmosphere in a large chamber at the temperatures present in the moon's upper atmosphere. To play the role of the sun's ultraviolet light hitting Titan's atmosphere, they used radio energy at a power level comparable to a modestly bright light bulb.
The UV light is important because it breaks up molecules such as molecular nitrogen or carbon monoxide in Titan's atmosphere, leaving the individual atoms to choose up different partners, forming new molecules.
The experiment yielded tiny aerosol particles. The team ran the particles through a sensitive mass spectrometer, which showed the chemical formulas for the molecules that made up the aerosols.
Ms. Hörst then ran the formulas past a roster of molecules biologically important for life on Earth. She got 18 hits, including the four nucleotides whose combinations form an organism's genetic information encoded in DNA.
In the end, she says, it appears to be less important that water is present to form these molecules than it is for some form of oxygen to be present in the mix of ingredients.
Enceladus's helping hand
On Earth, oxygen early in the planet's pre-life history would come in the form of carbon dioxide and carbon monoxide from volcanic activity, as well as from water released by volcanism and through meteor and comet impacts. On Titan, the oxygen appears to be coming from Enceladus, an intriguing moon of Saturn in its own right because of icy geysers spewing into space from near its south pole. Some researchers think the geysers hint at a subsurface sea - or at least sizable deposits of slush - and a potential habitat for life.
Last year, researchers showed how water molecules ejected as part of Enceladus's geysers can be carried great distances through the Saturn system. Some of those oxygen-bearing molecules make their way to Titan's neighborhood. If Titan's atmosphere indeed is forming nucleotides, amino acids, and perhaps other large biomolecules, and if this atmospheric chemistry factory is present on planets around other stars, that does not mean conditions there are right for combining these molecules in ways that lead to critters big or small, Hörst cautions.
On other planets and under other conditions, atmospheres "may not make these molecules," she says, "but they still might make other molecules" that life on Earth could could use.
***************************************************************************
Tropical lake on Titan? Surprising find could solve moon's methane mystery.
Scientists have wondered whether some unseen process replenishes the lakes of liquid methane on Titan, Saturn's biggest moon. A newly found lake suggests intriguing possibilities.
By Pete Spotts, Staff writer June 13, 2012
ESA/NASA/JPL/University of Arizona/USGS
Scientists have spotted a Great Salt Lake-scale patch of liquid methane on the surface of Saturn's moon Titan, along with smaller swamp-like features, in an unexpected and intriguing place.
Data from the Cassini spacecraft currently touring the Saturn system have already revealed lakes at Titan's poles, fed by summertime methane rain. But Cassini's radar found nothing similar at lower latitudes, and climate models have suggested that long-lived lakes might be impossible there.
Now, the discovery of the large, shallow lake in the moon's tropics may offer scientists clues about the processes driving a moon that has fascinating similarities to Earth before life emerged.
If the finding is confirmed by additional observations, it could imply the existence of significant subsurface methane deposits feeding the tropical lake. Or perhaps the moon recycles methane, with the liquid in polar lakes migrating underground back to the tropics, where it wells up again in lakes.
Whatever the cause, the discovery could have important implications for understanding how Titan maintains a methane cycle that is strikingly similar to the water cycle on Earth - with methane evaporating as gas, falling as rain, and gathering in lakes.
The report in Thursday's issue of the journal Nature represents a "significant discovery," says Tapio Schneider, a scientist at the California Institute of Technology who models planetary climates, including the moon Titan's.
On Earth, vast oceans are the source for the water cycle. On Titan, however, the known surface deposits of liquid methane are far too sparse to fully support the moon's methane cycle. That's because methane in the atmosphere readily breaks down into its components, carbon and hydrogen, when exposed to sunlight. Over the moon's 4.5 billion-year-old history, that process would have consumed all the known quantities of methane.
Something, it seemed, needed to be replenishing the moon's supply of surface methane. The lake in Titan's tropics, which appears to be a long-lived feature, may help identify one of the sources needed to sustain the cycle, researchers say.
The lake's location is key. The phrase "Titan's tropics" might seem like an oxymoron, considering that the moon's surface temperature averages minus 290 degrees Fahrenheit. Nevertheless, the moon's equatorial regions receive the most consistent sunlight throughout the course of its "year."
Previous climate studies "indicated convincingly that any liquid on Titan's tropical surface would quickly evaporate and be quickly transported to the pole," says Caitlin Griffith, a planetary scientist at the University of Arizona who led the team reporting the results.
Discovering the tropical lake "was completely unexpected," Dr. Griffith says. Cassini's travel mate, the European Space Agency's Huygens lander, seemed to reinforce that when it parachuted to the surface in 2005. Upon touchdown at a landing site within the equatorial belt, its sensors detected a brief puff of methane rising from a surface covered with sand-like ice grains. This suggested that it landed on a surface slightly dampened with the liquefied gas - but certainly no hydrocarbon lake or ocean, as some had expected.
Indeed, as Cassini continued its flybys of Titan, its radar found no lakes in the tropics, though it did find deep, vast lakes in polar regions. Yet now at least one lake appears to be present. How could Cassini have missed something the size of the Great Salt Lake in Utah?
At the radar's operating frequency, a body of liquid methane would have to be at least 26 feet (eight meters) deep in order to absorb all of the radio waves, giving it a pitch-black appearance on radar images. At shorter, near-infrared wavelengths, the liquid can be far shallower and still show up as black in the images. Those images revealed a black patch covering some 930 square miles (2,400 square kilometers) of Titan's tropical surface.
The team estimates the lake's depth to be at least three feet (one meter). In addition, it detected other, smaller patches of liquid methane from ankle to knee deep. So far, the team has analyzed only about 17 percent of the moon's tropics, so it's unclear if this lake and "wetlands" in the region represent more widespread surface features - in essence, oases spread throughout an otherwise arid belt encircling the moon, Griffith says.
Still, the find raises intriguing possibilities for understanding the moon's methane cycle. The lake and wetlands have been there since 2004, before Cassini scientists observed clouds and possible rainstorms in the tropics, notes CalTech's Dr. Schneider. That suggests "a subsurface source of methane," he writes in an e-mail exchange.
Modeling results he and colleagues published in January in Nature suggest methane at low and high latitudes could be linked either through as-yet undetected rivers on the surface or below the surface.
Or the tropics could harbor large subsurface deposits locally.
Griffith points out that Titan's orbit is nearly circular, but at one time would have been more elliptical that it is today. As Titan's orbit changed, the moon would have been stressed by Saturn's gravitational forces. This tugging and hauling would have generated heat in Titan's interior, perhaps melting methane ices and allowing them to migrate toward the surface.
Much of the scientific interest in Titan stems from the abundance of hydrocarbons such as methane in its atmosphere and on its surface, with abundances thought to be similar to those of the early Earth.
************************************************************************
Titan: Nasa scientists discover evidence 'that alien life exists on Saturn's moon'
Evidence that life exists on Titan, one of Saturn's biggest moons, appears to have been uncovered by Nasa scientists.
By Andrew Hough
8:30AM BST 05 Jun 2010
Researchers at the space agency believe they have discovered vital clues that appeared to indicate that primitive aliens could be living on the moon. Data from Nasa's Cassini probe has analysed the complex chemistry on the surface of Titan, which experts say is the only moon around the planet to have a dense atmosphere.
They suggest that life forms may have been breathing in the planet's atmosphere and also feeding on its surface's fuel. Astronomers claim the moon is generally too cold to support even liquid water on its surface. The research has been detailed in two separate studies. The first paper, in the journal Icarus, shows that hydrogen gas flowing throughout the planet's atmosphere disappeared at the surface. This suggested that alien forms could in fact breathe.
The second paper, in the Journal of Geophysical Research, concluded that there was lack of the chemical on the surface. Scientists were then led to believe it had been possibly consumed by life.
Researchers had expected sunlight interacting with chemicals in the atmosphere to produce acetylene gas. But the Cassini probe did not detect any such gas. Chris McKay, an astrobiologist at Nasa Ames Research Centre, at Moffett Field, California who led the research, said: "We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan, similar to the way we consume oxygen on Earth.
"If these signs do turn out to be a sign of life, it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth." Professor John Zarnecki, of the Open University, added: "We believe the chemistry is there for life to form. It just needs heat and warmth to kick-start the process.
"In four billion years' time, when the Sun swells into a red giant, it could be paradise on Titan."
They warned, however, that there could be other explanations for the findings. But taken together, they two indicate two important conditions necessary for methane-based life to exist.
****************************************************************************
What is Consuming Hydrogen and Acetylene on Titan?
06.03.10
Two new papers based on data from NASA's Cassini spacecraft scrutinize the complex chemical activity on the surface of Saturn's moon Titan. While non-biological chemistry offers one possible explanation, some scientists believe these chemical signatures bolster the argument for a primitive, exotic form of life or precursor to life on Titan's surface. According to one theory put forth by astrobiologists, the signatures fulfill two important conditions necessary for a hypothesized "methane-based life."
One key finding comes from a paper online now in the journal Icarus that shows hydrogen molecules flowing down through Titan's atmosphere and disappearing at the surface. Another paper online now in the Journal of Geophysical Research maps hydrocarbons on the Titan surface and finds a lack of acetylene.
This lack of acetylene is important because that chemical would likely be the best energy source for a methane-based life on Titan, said Chris McKay, an astrobiologist at NASA Ames Research Center, Moffett Field, Calif., who proposed a set of conditions necessary for this kind of methane-based life on Titan in 2005. One interpretation of the acetylene data is that the hydrocarbon is being consumed as food. But McKay said the flow of hydrogen is even more critical because all of their proposed mechanisms involved the consumption of hydrogen.
"We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan, similar to the way we consume oxygen on Earth," McKay said. "If these signs do turn out to be a sign of life, it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."
To date, methane-based life forms are only hypothetical. Scientists have not yet detected this form of life anywhere, though there are liquid-water-based microbes on Earth that thrive on methane or produce it as a waste product. On Titan, where temperatures are around 90 Kelvin (minus 290 degrees Fahrenheit), a methane-based organism would have to use a substance that is liquid as its medium for living processes, but not water itself. Water is frozen solid on Titan's surface and much too cold to support life as we know it.
The list of liquid candidates is very short: liquid methane and related molecules like ethane. While liquid water is widely regarded as necessary for life, there has been extensive speculation published in the scientific literature that this is not a strict requirement.
The new hydrogen findings are consistent with conditions that could produce an exotic, methane-based life form, but do not definitively prove its existence, said Darrell Strobel, a Cassini interdisciplinary scientist based at Johns Hopkins University in Baltimore, Md., who authored the paper on hydrogen.
Strobel, who studies the upper atmospheres of Saturn and Titan, analyzed data from Cassini's composite infrared spectrometer and ion and neutral mass spectrometer in his new paper. The paper describes densities of hydrogen in different parts of the atmosphere and the surface. Previous models had predicted that hydrogen molecules, a byproduct of ultraviolet sunlight breaking apart acetylene and methane molecules in the upper atmosphere, should be distributed fairly evenly throughout the atmospheric layers.
Strobel found a disparity in the hydrogen densities that lead to a flow down to the surface at a rate of about 10,000 trillion trillion hydrogen molecules per second. This is about the same rate at which the molecules escape out of the upper atmosphere. "It's as if you have a hose and you're squirting hydrogen onto the ground, but it's disappearing," Strobel said. "I didn't expect this result, because molecular hydrogen is extremely chemically inert in the atmosphere, very light and buoyant. It should 'float' to the top of the atmosphere and escape."
Strobel said it is not likely that hydrogen is being stored in a cave or underground space on Titan. The Titan surface is also so cold that a chemical process that involved a catalyst would be needed to convert hydrogen molecules and acetylene back to methane, even though overall there would be a net release of energy. The energy barrier could be overcome if there were an unknown mineral acting as the catalyst on Titan's surface.
The hydrocarbon mapping research, led by Roger Clark, a Cassini team scientist based at the U.S. Geological Survey in Denver, examines data from Cassini's visual and infrared mapping spectrometer. Scientists had expected the sun's interactions with chemicals in the atmosphere to produce acetylene that falls down to coat the Titan surface. But Cassini detected no acetylene on the surface.
In addition Cassini's spectrometer detected an absence of water ice on the Titan surface, but loads of benzene and another material, which appears to be an organic compound that scientists have not yet been able to identify. The findings lead scientists to believe that the organic compounds are shellacking over the water ice that makes up Titan's bedrock with a film of hydrocarbons at least a few millimeters to centimeters thick, but possibly much deeper in some places. The ice remains covered up even as liquid methane and ethane flow all over Titan's surface and fill up lakes and seas much as liquid water does on Earth.
"Titan's atmospheric chemistry is cranking out organic compounds that rain down on the surface so fast that even as streams of liquid methane and ethane at the surface wash the organics off, the ice gets quickly covered again," Clark said. "All that implies Titan is a dynamic place where organic chemistry is happening now."
The absence of detectable acetylene on the Titan surface can very well have a non-biological explanation, said Mark Allen, principal investigator with the NASA Astrobiology Institute Titan team. Allen is based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. Allen said one possibility is that sunlight or cosmic rays are transforming the acetylene in icy aerosols in the atmosphere into more complex molecules that would fall to the ground with no acetylene signature.
"Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed," Allen said. "We have a lot of work to do to rule out possible non-biological explanations. It is more likely that a chemical process, without biology, can explain these results - for example, reactions involving mineral catalysts."
"These new results are surprising and exciting," said Linda Spilker, Cassini project scientist at JPL. "Cassini has many more flybys of Titan that might help us sort out just what is happening at the surface."
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL.
For more information about the Cassini-Huygens mission visit http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov.
***********************************************************************
Oxygen detected in atmosphere of Saturn's moon Dione: Discovery could mean ingredients for life are abundant on icy space bodies
Date:
March 2, 2012
Los Alamos National Laboratory scientists and an international research team have announced discovery of molecular oxygen ions (O2+) in the upper-most atmosphere of Dione, one of the 62 known moons orbiting the ringed planet. The research appeared recently in Geophysical Research Letters and was made possible via instruments aboard NASA's Cassini spacecraft, which was launched in 1997.
Dione -- discovered in 1684 by astronomer Giovanni Cassini (after whom the spacecraft was named) -- orbits Saturn at roughly the same distance as our own moon orbits Earth. The tiny moon is a mere 700 miles wide and appears to be a thick, pockmarked layer of water ice surrounding a smaller rock core. As it orbits Saturn every 2.7 days, Dione is bombarded by charged particles (ions) emanating from Saturn's very strong magnetosphere. These ions slam into the surface of Dione, displacing molecular oxygen ions into Dione's thin atmosphere through a process called sputtering.
Molecular oxygen ions are then stripped from Dione's exosphere by Saturn's strong magnetosphere.
A sensor aboard the Cassini spacecraft called the Cassini Plasma Spectrometer (CAPS) detected the oxygen ions in Dione's wake during a flyby of the moon in 2010. Los Alamos researchers Robert Tokar and Michelle Thomsen noted the presence of the oxygen ions.
"The concentration of oxygen in Dione's atmosphere is roughly similar to what you would find in Earth's atmosphere at an altitude of about 300 miles," Tokar said. "It's not enough to sustain life, but -- together with similar observations of other moons around Saturn and Jupiter -- these are definitive examples of a process by which a lot of oxygen can be produced in icy celestial bodies that are bombarded by charged particles or photons from the Sun or whatever light source happens to be nearby."
Perhaps even more exciting is the possibility that on a moon with subsurface water, such as Jupiter's moon Europa, molecular oxygen could combine with carbon in subsurface lakes to form the building blocks of life. Future missions to Europa could help unravel questions about that moon's habitability.
Two sensors aboard Cassini built by Los Alamos National Laboratory are expected to come into play beginning later this month, and again in April and May, when the Cassini spacecraft flies by the moon Enceladus. The moon is one of the brightest objects in our solar system, reflecting back nearly all of the sunlight that strikes it, thanks to a shimmering surface of snowy ice crystals. The moon also unleashes plumes ofmaterial from its south polar region. Los Alamos' ion-beam spectrometer and ion-mass spectrometer may help answer key questions about the composition of these plumes.
****************************************************************************
Oxygen found on Saturn's moon Rhea
Nasa's Cassini probe has scooped oxygen from the thin atmosphere of Rhea - the first time the gas has been detected directly on another world
Thursday 25 November 2010 19.00 GMT
A spacecraft has tasted oxygen in the atmosphere of another world for the first time while flying low over Saturn's icy moon, Rhea.
Nasa's Cassini probe scooped oxygen from the thin atmosphere of the planet's moon while passing overhead at an altitude of 97km in March this year. Until now, wisps of oxygen have only been detected on planets and their moons indirectly, using the Hubble space telescope and other major facilities.
Instruments aboard Cassini revealed an extremely thin oxygen and carbon dioxide atmosphere that is sustained by high-energy particles slamming into the moon's surface and kicking up atoms, molecules and ions.
Astronomers have counted 62 moons orbiting Saturn. At 1500km wide, Rhea is the second largest and is thought to be made almost entirely of ice. "This really is the first time that we've seen oxygen directly in the atmosphere of another world," said Andrew Coates, at UCL's Mullard Space Science Laboratory, a co-author of the study published in the journal Science.
"Active, complex chemistry involving oxygen may be quite common throughout the solar system and even our universe," said team leader Ben Teolis of Southwest Research Institute in San Antonio, Texas. "Such chemistry could be a prerequisite for life. All evidence from Cassini indicates that Rhea is too cold and devoid of the liquid water necessary for life as we know it."
Rhea's atmosphere makes it unique in the Saturn system. Only Rhea and Titan, the largest Saturnian moon, have enough mass to hold on to an atmosphere with their gravity. Titan, however, has a very thick nitrogen and methane atmosphere, with very little carbon dioxide and oxygen.
Astronomers have previously used telescopes to detect oxygen in the atmospheres of Jupiter's moons Europa and Ganymede, but similar searches drew a blank on Rhea because the concentration of the gas was so low. According to instruments aboard Cassini, every cubic metre of Rhea's atmosphere contains around 50bn oxygen molecules and 20bn carbon dioxide molecules. The carbon dioxide may come from dry ice trapped within the moon, or be produced by high-energy particles striking water ice on Rhea. Another source could be carbon-rich materials deposited by tiny meteors that have bombarded Rhea's surface.
***********************************************************************
6 Most Likely Places for Alien Life in the Solar System
by Seth Shostak, Senior Astronomer, SETI Institute | May 16, 2012 01:05pm ET
Life Across the Solar System?
We still don't have hard evidence for any life that's not of this Earth, but across our solar system there are some tantalizing possibilities for primitive life to find a haven. Some moons of Jupiter and Saturn are intriguing, and there's also the chance for some surprises somewhere on Mars.
Here are my top six candidates for the best spots to search for primitive alien life in our solar system.
FIRST STOP: Enceladus
Seth Shostak is a senior astronomer at the SETI Institute in Mountain View, Calif.
Enceladus
In 2005, NASA's Cassini spacecraft photographed geysers of frozen water spewing from cracks in Enceladus' southern hemisphere. Scientists think reservoirs of liquid water lie beneath the frozen surface and are warmed by gravitational interactions between Enceladus and other moons around Saturn. The necessities for life are there, and maybe Enceladans are as well. The moon has a mean radius of 156.6 miles (252.1 km). [Photos: Enceladus, Saturn's Cold, Bright Moon]
NEXT STOP: Mars
Mars remains perennially popular for those hunting for otherworldly protoplasm. Particularly intriguing are the dark stripes that appear in the Martian summertime at Horowitz crater. These are likely to be salty meltwater only inches beneath Mars' dusty epidermis. A relatively simple probe could sample this muddy environment. Mars has a diameter of about 4,212 miles (6,779 km).
NEXT STOP: Titan
Titan is Saturn's largest moon and the only world in the solar system (besides Earth) known to sport liquid lakes. These are lakes of ethane and methane - liquid natural gas - endlessly topped up by hydrocarbon rain. Despite the odd ingredients and Titan's gelid temperatures (minus 290 Fahrenheit, or minus 179 Celsius), it is a world where chemistry's a happening enterprise. Titan possesses diameter of 3,200 miles (5,150 km).
NEXT STOP: Europa
Many would grant Europa a higher potential-life rating than I have, since there's probably more liquid water here than in all of Earth's oceans. The downside is that Europa's vast, salty seas lie beneath roughly 10 miles of ice. Not only is it difficult get a probe beneath this icy armor, but Europa's oceans are darker than a cave - which means photosynthesis won't work. However, something down there may subsist on geothermal heat or complex molecules from the surface. Europa possesses a mean radius of 970 miles (1,560.8 km).
NEXT STOP: Venus, the Hellish Planet
A surprise entry in the exobiology sweepstakes is our sister planet, Venus, with its scorching surface temperatures (850 F, or 454 C). The planet is generally assumed to be as sterile as a boiled mule.
But planetary scientist David Grinspoon, astrobiology curator at the Denver Museum of Nature and Science, points out that high in the Venusian atmosphere temperatures are refreshingly tolerable. Atmospheric sulfur dioxide and carbon monoxide might serve as food for floating microbes. Venus is 7,521 miles wide (12,104 km).
NEXT STOP: Callisto and Ganymede of Jupiter
Callisto and Ganymede
I considered these two moons of Jupiter together, as I feel they're neck-and-neck candidates for biology. Like their more celebrated neighbor Europa, Ganymede andCallisto may have buried, liquid oceans. However, in the case of these two satellite siblings, briny deeps would underlie at least 60 miles (100 km) of rock. Finding inhabitants here is a shovel-ready project for our grandkids. Callisto has a diameter of more than 2,985 miles (4,800 km); Ganymede's diameter is 3,270 miles (5,262.4 km).
Hi Rad,
This is interesting timing as you pointed out... I´d like to ask why does Pluto correlate with organic life?
Thank you
All the best
Quote from: Skywalker on Dec 12, 2014, 03:12 AM
Hi Rad,
This is interesting timing as you pointed out... I´d like to ask why does Pluto correlate with organic life?
Thank you
All the best
Hi Skywalker,
Because it correlates with the 'bonding' of various elements, chemicals, etc that allow the various forms of life to exist: because of the bonding.
God Bless, Rad