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| 18 Jan 2013 07:25 PM |
Lakes on Saturn's moon Titan reflect radio waves in varying ways in this image from NASA's Cassini spacecraft. It's not exactly icing on a cake, but it could be icing on a lake. A new paper by scientists on NASA's Cassini mission finds that blocks of hydrocarbon ice might decorate the surface of existing lakes and seas of liquid hydrocarbon on Saturn's moon Titan. The presence of ice floes might explain some of the mixed readings Cassini has seen in the reflectivity of the surfaces of lakes on Titan.
"One of the most intriguing questions about these lakes and seas is whether they might host an exotic form of life," said Jonathan Lunine, a paper co-author and Cassini interdisciplinary Titan scientist at Cornell University, Ithaca, N.Y. "And the formation of floating hydrocarbon ice will provide an opportunity for interesting chemistry along the boundary between liquid and solid, a boundary that may have been important in the origin of terrestrial life."
Titan is the only other body besides Earth in our solar system with stable bodies of liquid on its surface. But while our planet's cycle of precipitation and evaporation involves water, Titan's cycle involves hydrocarbons like ethane and methane. Ethane and methane are organic molecules, which scientists think can be building blocks for the more complex chemistry from which life arose. Cassini has seen a vast network of these hydrocarbon seas cover Titan's northern hemisphere, while a more sporadic set of lakes bejewels the southern hemisphere.
Up to this point, Cassini scientists assumed that Titan lakes would not have floating ice, because solid methane is denser than liquid methane and would sink. But the new model considers the interaction between the lakes and the atmosphere, resulting in different mixtures of compositions, pockets of nitrogen gas, and changes in temperature. The result, scientists found, is that winter ice will float in Titan's methane-and-ethane-rich lakes and seas if the temperature is below the freezing point of methane -- minus 297 degrees Fahrenheit (90.4 kelvins). The scientists realized all the varieties of ice they considered would float if they were composed of at least 5 percent "air," which is an average composition for young sea ice on Earth. ("Air" on Titan has significantly more nitrogen than Earth air and almost no oxygen.)
If the temperature drops by just a few degrees, the ice will sink because of the relative proportions of nitrogen gas in the liquid versus the solid. Temperatures close to the freezing point of methane could lead to both floating and sinking ice – that is, a hydrocarbon ice crust above the liquid and blocks of hydrocarbon ice on the bottom of the lake bed. Scientists haven't entirely figured out what color the ice would be, though they suspect it would be colorless, as it is on Earth, perhaps tinted reddish-brown from Titan's atmosphere.
"We now know it's possible to get methane-and-ethane-rich ice freezing over on Titan in thin blocks that congeal together as it gets colder -- similar to what we see with Arctic sea ice at the onset of winter," said Jason Hofgartner, first author on the paper and a Natural Sciences and Engineering Research Council of Canada scholar at Cornell. "We'll want to take these conditions into consideration if we ever decide to explore the Titan surface some day."
Cassini's radar instrument will be able to test this model by watching what happens to the reflectivity of the surface of these lakes and seas. A hydrocarbon lake warming in the early spring thaw, as the northern lakes of Titan have begun to do, may become more reflective as ice rises to the surface. This would provide a rougher surface quality that reflects more radio energy back to Cassini, making it look brighter. As the weather turns warmer and the ice melts, the lake surface will be pure liquid, and will appear to the Cassini radar to darken.
"Cassini's extended stay in the Saturn system gives us an unprecedented opportunity to watch the effects of seasonal change at Titan," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We'll have an opportunity to see if the theories are right."
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and ASI, the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington.
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Cazamal
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| Joined: 07 Jul 2013 |
| Total Posts: 1256 |
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| 06 Feb 2014 08:38 PM |
cool
but this is global, not solar system
¡La migra! ¡Correr! |
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Dulexo
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| Joined: 07 Mar 2015 |
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| 06 Feb 2014 10:01 PM |
There's no water on Titan.
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| 06 Feb 2014 10:46 PM |
| We need water in order to gave life. Liquid methane is the exact sane thing on Neptune... Water is the only thing available thing for life. Without water, we wouldn't exist kid. Learn some science. NASA has concluded that Titan is deserted, lifeless, and is no hope for life because it is 30 times belowvl freezing. |
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| 07 Feb 2014 01:51 AM |
Mr, NASA never colnluded that. There is no set of rules for life, we've never discovered anylife besides that on earth, so how do we know how Aliens would form? It's completely possible for life to be on Titan, Water is the building block of life for Carbon based lifeforms such as Humans, There are other forms of life that could be Hydrogen based, silican based? Hell even methane based, we don't know yet. Just because We're carbon based doesn't mean all life is, you never know, we could be a strange race for being carbon based. |
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Dulexo
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| Joined: 07 Mar 2015 |
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| 07 Feb 2014 02:05 AM |
^ True
Fun fact: Aliens from other parts of our galaxy or other galaxies will not be green, instead will be black to gray because the lack of Iron.
Also, what the guy said above, while we haven't discovered life, we have discovered fossils on Mars [there used to be water on Mars] and water on the Moon, we were lucky to get the right orbit, not too cold or too hot, but in other galaxies aliens could be made out of different elements, maybe some we haven't discovered [a really good chance we've only discovered 0.01% of all elements in the universe] so aliens could be made out of plasma or metal for all we know. |
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| 07 Feb 2014 02:09 AM |
^ Exactly. I really hope there is life in our Galaxy though. If there isn't life in the Milky way then well most likely never find life for 4 Billion years when Andromeda and the Milky way collide. |
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Dulexo
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| Joined: 07 Mar 2015 |
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| 07 Feb 2014 02:15 AM |
^
there's no proof we'll collide with it.
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| 07 Feb 2014 02:17 AM |
| Well, then we better hope there is life in our galaxy because if there isn't we will probably never ever see it plainly because of the Massive distances between galaxies. |
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Dulexo
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| Joined: 07 Mar 2015 |
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| 07 Feb 2014 02:21 AM |
WAT IF THE SKY IS CIA CONSPIRACY ITS JUST A LED SCREEN |
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| 10 Feb 2014 10:37 PM |
| That's not possible. I've seen on National Geo, Science even YouTube, and they concluded rusty no life is on Titan. Street I still can't believe you still do forums lol. But Titan is unsuitable for life, way too cold, lack of sunlight, heck its not even a planet. And its too far way too far from the sun. The cloud is similar to Venus. Even the water is poisones. We need liquid water, not liquid nitrogen. Liquid WATER is the only essential and known thing to have life. Heck even Mars have no water. It has dry ice, barely any. |
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| 11 Feb 2014 11:22 AM |
| Mr, life is entirely possible, life could be based in Liquid methane, how cold the place it is, is irrelivent, life could exist in water, under antartica, in similar conditions to that on titan. |
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| 11 Feb 2014 05:06 PM |
| I hear plankton aren't carbon-based, rather, they're silicate based. Look at the anaerobes everywhere too. Well, you can't see them since most of them are all microscopic. Life on earth is based on an electron acceptor to make ATP, aerobes are best, since they use oxygen, but methane is a gas that can be used. |
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| 11 Feb 2014 06:29 PM |
@dulexo He men't a methane lake on titan has frozen did you know it rains methane on titan? |
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