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Cassini Finds Evidence For Ocean Inside Titan
Riding with Robots writes "NASA reports that by using data from the Cassini probe's radar, scientists established the locations of 50 unique landmarks on the surface of Saturn's planet-size moon Titan. They then searched for these same lakes, canyons and mountains in the data after subsequent Titan flybys. They found that the features had shifted from their expected positions by up to 30 kilometers. NASA says a systematic displacement of surface features would be difficult to explain unless the moon's icy crust was decoupled from its core by an internal ocean, making it easier for the crust to move. If confirmed, this discovery would add to the growing list of moons in the solar system that are icy on the outside and warm and liquid inside, providing potential habitats. We've previously discussed Titan's hydrocarbon lakes and potential cryovolcano."
Titan is one of the most exciting bodies in our solar system. Having recently read Carl Sagan's Pale Blue Dot, he wrote a fair bit about the abundance of organic molecules on Titan. We seem to keep discovery more and more exciting things about this moon. It's probably still unlikely that there is life on it, but it sure would be interesting to send a probe in to it and see what we can discover.
Life ON gas giants seems like a big NO with what we currently know about the conditions required for life to emerge. But life around gas giants, on their moons seems plausible.
What I'd like to know (read: what I'd like some slashdotter with the required know-how explain to me) is why are these moons hot on the inside, possibly hot enough for water ice to turn into liquid water. It's so incredibly far away from the sun. Is this caused by their size and subsequent internal dynamics?
Also, aren't these moons constantly bombarded with radiation from their host planet's powerful magnetic field? Must be rough for aliens.
While it is very likely that the interiors of a couple moons in the solar system have subsurface liquid oceans, that does not indicate high enough temperature at depth to consider the interior warm or hot or capable of supporting life. Over geologic time these subsurface liquids (which are thought to be predominantly H2O) have more likely formed through interaction with surrounding rock/metal. As H2O reacts with its surroundings and incorporates various impurities (salts, ammonia, organic molecules) into its structure the melting point is decreased to the point that a liquid or fluid condition is possible at significantly lower temperatures. Although in the case of Ganymede (Jupiter's fourth moon), which posses an internally generated magnetic field, a dynamo action similar to Earth's core may exist providing heat. Whether this is the case on Titan is yet to be determined. The massive amounts of organic components there make it harder to determine if there is an internal heat source or if the mixture of organic compounds are naturally stable at those conditions creating the lakes and cryovolcanoes previously mentioned.
Not to be rude, but actually this is incorrect. At low pressures there is some odd behavoir, but on a planetary scale the melting point of water increases with increasing pressure. Ice has several different crystal structures called polymorphs that change as pressure increases. Each requires greater and greater temperature to melt. This is a good page on the water molecule and its behavoir: http://www.lsbu.ac.uk/water/index2.html.
Too bad Arthur C. Clarke passed away on Tuesday (Wed. in Sri Lanka), he would have been very pleased to have his suspicions confirmed like this. Then again, maybe he's hanging with Dave Bowman and HAL. In that case his response might be whatever a stylish English gentleman says instead of "Duh!".
Rest in peace, Sir Arthur, and thanks for giving us "all these worlds."
-- a sad fan who's enjoyed your books for over 20 yearsQuantum mechanics: the dreams that stuff is made of.
I think the biggest difficulty would be power. Our Mars rovers have been solar powered, but it's unlikely that that would work on Titan, since it's much farther from the Sun, and its atmosphere will block most of what little light does reach it, since it's basically opaque. All of our outer solar systems probes have been nuclear powered, and there might be difficulties in engineering that to fit on a rover and provide sufficient power. A rover would also have to contend with the weather (it rains methane), and the atmosphere might pose a challenge for radio communications to orbit. I don't think any of these challenges are insurmountable, but they definitely mean that we can't just drop a rover engineered for Mars on Titan -- it will take an entirely new design.
So now there's Europa and now Titan that have probable underground oceans, and oceans seem like good candidates for life.
It would be interesting, if in the future, we find that most life actually forms on moons with oceans protected from the vaccum of space.
Maybe out planet, with it's skin lain bare to the cosmos, is an exception for a life-harboring world. Maybe this is why we haven't heard from any other intelligent lifeforms; perhaps they all have severe agoraphobia and just freak-out when they send their first probes up through the surface.
Let's hope the wouldn't suffer from the Krikkit xenophobic mindset, or we might be finding out exactly how good we humans are at international...er, interplanetary negotiations...oh my, I certainly hope we don't have to find out!
Read my Very Short "Stories"
You might like to have a look at "Slow Life", by Michael Swanwick.
http://www.analogsf.com/Hugos/slowlife.shtml
It's a nice sci-fi novelette (that won the Hugo in 2003) about life in the deep seas of Titan.
http://www.nicholaswhyte.info/sf/Hugo2003.htm
http://www.locusmag.com/SFAwards/Db/Hugo2003.html#nvt
"Is there life on Titan? Probably not. It's cold down there! 94 Kelvin is the same as -179 Celsius, or -290 Fahrenheit. And yet . . . life is persistent. It's been found in Antarctic ice and in boiling water in submarine volcanic vents. Which is why we'll be paying particular attention to exploring the depths of the ethane-methane sea. If life is anywhere to be found, that's where we'll find it."
Science fiction: 2001, Star Trek, Lost in Space, ...
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Science: space probes, lunar landings,
Engineering: solar power satellites, industrial microgravity,
Industry: weather satellites, communication satellites, GPS,
Science leads to spinoffs in multiple directions. Science fiction is one of them. New industries are another. We're in a Red Queen's Race here, and stopping all the science won't speed us up much, but it'll sure make it harder to keep running.
If you're worried about wasted money, don't look to Cape Canaveral, look to Baghdad.