iNow Posted June 6, 2010 Posted June 6, 2010 So, it seems these reactions on Saturn's moon cannot be accounted for by chemical interactions induced by the sun, so a few parallel studies have concluded life exists on Titan based on evidence available. What do you think? http://www.telegraph.co.uk/science/space/7805069/Titan-Nasa-scientists-discover-evidence-that-alien-life-exists-on-Saturns-moon.html Evidence that life exists on Titan, one of Saturn’s biggest moons, appears to have been uncovered by Nasa scientists. <...> 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 have discovered that life forms 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. <more at the link>
jimmydasaint Posted June 6, 2010 Posted June 6, 2010 iNow - I think that the find is actually politically and economically motivated rather than being a scientific coup. Last time NASA needed funding we lived in financially straitened times. Funding for non-essential projects seemed to be decreasing. NASA is an excellent source of intellectual activity that demands funding non-stop. And, suddenly, there were reports of the Martian 'bacterium' Martian 'bacteria' This time, we are still in a recession. funding is short, non-essential projects are losing funds and, strike me down with a feather, we may have found new life on Titan! I think it shows that NASA are show political nous in funding their well-deserved projects. Is it ethical to come up with dramatic scenarios to drum up financial support? Absolutely not. But we live in strange times...
Cap'n Refsmmat Posted June 6, 2010 Posted June 6, 2010 http://www.nasa.gov/topics/solarsystem/features/titan20100603.html The NASA press release is much more cautious, and notes that there can be non-biological explanations for the observations.
ydoaPs Posted June 6, 2010 Posted June 6, 2010 http://www.nasa.gov/topics/solarsystem/features/titan20100603.html The NASA press release is much more cautious, and notes that there can be non-biological explanations for the observations. See above.
Moontanman Posted June 6, 2010 Posted June 6, 2010 I agree, the NASA release was very cautious, we really know very little about planetary chemistry at the temperatures on Titan. However if we were to find life so much different than earth life that it could develop and grow under the conditions on Titans surface it would say quite a bit about the prospects for wide spread life in the universe. Complex life on Titan would be an outrageous discovery and would pretty much destroy most theories that assert life is rare or has to be "just like us" Not just a bomb shell type moment , more like another "big bang"
Airbrush Posted June 9, 2010 Posted June 9, 2010 "A mixture of hydrocarbons, such as the methane/ethane lakes detected on Titan by the Cassini spacecraft, could act as a solvent over a wide range of temperatures but would lack polarity. "Isaac Asimov, the biochemist and science fiction writer, suggested that poly-lipids could form a substitute for proteins in a non-polar solvent such as methane or liquid hydrogen. "A proposal has been made that life on Mars may exist and be using a mixture of water and hydrogen peroxide as its solvent. A 61.2 percent (by weight) mix of water and hydrogen peroxide has a freezing point of -56.5 degrees Celsius, and also tends to super-cool rather than crystallize. It is also hygroscopic, an advantage in a water-scarce environment." http://en.wikipedia.org/wiki/Alternative_biochemistry#Other_solvents I don't understand these fully. Does it imply that a solvent of methane/ethane could be promising as a medium for exotic life?
Moontanman Posted June 9, 2010 Posted June 9, 2010 "A mixture of hydrocarbons, such as the methane/ethane lakes detected on Titan by the Cassini spacecraft, could act as a solvent over a wide range of temperatures but would lack polarity. "Isaac Asimov, the biochemist and science fiction writer, suggested that poly-lipids could form a substitute for proteins in a non-polar solvent such as methane or liquid hydrogen. "A proposal has been made that life on Mars may exist and be using a mixture of water and hydrogen peroxide as its solvent. A 61.2 percent (by weight) mix of water and hydrogen peroxide has a freezing point of -56.5 degrees Celsius, and also tends to super-cool rather than crystallize. It is also hygroscopic, an advantage in a water-scarce environment." http://en.wikipedia.org/wiki/Alternative_biochemistry#Other_solvents I don't understand these fully. Does it imply that a solvent of methane/ethane could be promising as a medium for exotic life? Yes, basically that is what they are saying, silicon life might use these hydrocarbons as a solvent as well. Silicon (not silicone) is more stable at the low temps and will dissolve in hydrocarbons like methane.
iNow Posted June 9, 2010 Author Posted June 9, 2010 Bad Astronomy gave an update yesterday: http://blogs.discovermagazine.com/badastronomy/2010/06/07/has-life-on-titan-been-discovered-no/ There has been a bit of an uproar the past day or so that scientists have found evidence of life on Saturn’s giant moon Titan. As soon as I saw the press release I knew this was going to be a problem. So let’s be clear: First, have we found life on Titan? No. Have we found evidence that there might be life on Titan? Sorta. The results are preliminary and not yet confirmed; in fact, some of the evidence is from computer modeling and has not been directly observed. Bear in mind as well that evidence is not proof. Evidence just means an observation was made that is consistent with life on the moon, but doesn’t say much else. There are non-biological explanations for the observations as well. Of course, speculation is running rampant, so much so that Chris McKay, an exobiologist who studies Titan, has released an article clearing things up. First, a little background. Titan is a monster, the second biggest moon in the solar system at 5150 km (3200 miles) in diameter. If it weren’t orbiting Saturn, it would probably be considered a planet in its own right: it’s bigger than Mercury and Pluto. It has a thick atmosphere, made up of nitrogen, methane, and other molecules. It’s very cold, but it’s known that lakes, probably of liquid methane, exist on the surface. Five years ago, McKay and other scientists pointed out that if methane-based life existed on Titan, it might be detectable through a surface depletion of ethane, hydrogen, and acetylene. New observations show that this is the case; there are lower amounts of these substances than the chemistry of Titan would indicate. As McKay points out, "This is a still a long way from ‘evidence of life’. However, it is extremely interesting." ...Continue reading
Moontanman Posted June 9, 2010 Posted June 9, 2010 You are of course correct inow, sadly most people will not read far enough past the headlines to get the real story, life on titan would be really cool but i wonder how difficult it might be to confirm, how do you actually look for life at the temps of titan, do we have the ability to do much more than say it might be? Unless we are talking complex life (even then it might be difficult to get real evidence) detecting life on Titan would be a nightmare i am sure. How do you send a microscope to another planet to see microscopic life forms that will be close to impossible to find even if we were there in person. I have a feeling that until we are there in person this will remain speculation.
PaulS1950 Posted June 10, 2010 Posted June 10, 2010 It is no harder to send a microscope than it is to send a telescope. after all a microscope is just a telescope turned around... with some refinements.
Airbrush Posted June 10, 2010 Posted June 10, 2010 Yes, a robotic mission could land an electron microscope on Titan. It could walk around like an insect looking for stuff to examine very closely and radio it back to Earth.
Moontanman Posted June 11, 2010 Posted June 11, 2010 It is no harder to send a microscope than it is to send a telescope. after all a microscope is just a telescope turned around... with some refinements. Who's gonna place specimens on the slides? I'm not convinced an electron microscope could be used like that.
Cap'n Refsmmat Posted June 11, 2010 Posted June 11, 2010 Electron microscopes don't work anything like optical telescopes or microscopes. You'd need some specialist equipment to have it load automatically.
ydoaPs Posted June 11, 2010 Posted June 11, 2010 I'm not sure why one would want to utilize an electron microscope in this case, anyway.
Airbrush Posted June 12, 2010 Posted June 12, 2010 I proposed an electron microscope (EM) for maximum magnification. Opticals go up to only about 2,000x, but EMs magnify 1,000,000x. What the heck, send both. If an EM is too heavy, either miniateurize it, or send several of the most capable optical microscopes available. Send all sorts of other kinds of sensory devices to sniff and taste that stuff thoroughly. The process of taking samples of the liquid methane lakes, or other strange stuff, can easily be transported to an examination station. Detailed HD video is sent to Earth with a one-hour delay.
ydoaPs Posted June 12, 2010 Posted June 12, 2010 Wouldn't the level of magnification provided by an electron microscope be somewhat useless in trying to study assemblies of macromolecules such as life?
Airbrush Posted June 13, 2010 Posted June 13, 2010 Wouldn't the level of magnification provided by an electron microscope be somewhat useless in trying to study assemblies of macromolecules such as life? You are probably right. I am not familiar with this field. Then let's send the most appropriate sensory devices for the job. OK, it IS rocket science, but probably doable with current technology. The real problem is money to finance this mission, with other competing mission proposals.
Realitycheck Posted June 14, 2010 Posted June 14, 2010 This doesn't add up. Here, Strobel claims that all of this free-floating H is supposed to be freed when uv light interacts with methane and/or acetylene at the top of the atmosphere, which supposedly sinks down into the rest of the atmosphere. Strobel's computer simulations suggest a hydrogen flow down to the surface at a rate of about 10,000 trillion trillion molecules per second. However, in the next paragraph he explains how "molecular hydrogen is extremely chemically inert in the atmosphere, very light and buoyant. It should 'float' to the top of the atmosphere and escape." Therefore, all of this molecular hydrogen that supposedly sank to the surface that these aliens were supposed to be breathing never should have made it there. It should have "escaped" from the atmosphere to begin with, end of story. And here, they are saying the error was due to a computer miscalculation. Like I said, it didn't add up.
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