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Cassini Finds Evidence For Ocean Inside Titan

Soulskill posted more than 6 years ago | from the so-that's-where-it-was-hiding dept.

Space 79

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."

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79 comments

Exciting. (2, Insightful)

Daemonax (1204296) | more than 6 years ago | (#22814098)

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.

Re:Exciting. (5, Informative)

Anonymous Coward | more than 6 years ago | (#22814136)

"it sure would be interesting to send a probe in to it and see what we can discover."

We have sent The Huygens Probe [wikipedia.org] Before, but it was not designed to look for an underwater ocean. Lets hope they return with somthing else.

Re:Exciting. (2, Funny)

McGiraf (196030) | more than 6 years ago | (#22815080)

"but it was not designed to look for an underwater ocean"

Well if you know how to design such a thing I think you could patent it an NOBODY on slashdot would complain about this patent.

Underwater ocean? (1)

Criliric (879949) | more than 6 years ago | (#22815480)

i actually had to read that one a few times, to make sure i read it right :S

Re:Exciting. (1)

iminplaya (723125) | more than 6 years ago | (#22815620)

...an underwater ocean.

I think we got some of those right here on earth.

Lets hope they return with somthing else.

A boat?

Just sit right back and you'll hear a tale,
A tale of a fateful trip
That started from this tropic port
Aboard this tiny ship...

Re:Exciting. (5, Funny)

owlnation (858981) | more than 6 years ago | (#22814498)

Titan is one of the most exciting bodies in our solar system.
Of course, what you say is technically correct. But we really need a different way of expressing it, because when I read: "most exciting bodies in our solar system," I immediately thought: "Jessica Biel".

I suspect I was not alone.

Re:Exciting. (5, Funny)

ChameleonDave (1041178) | more than 6 years ago | (#22814734)

It is still correct to say that it would be interesting to send a probe into it, though.

Re:Exciting. (2, Insightful)

layer3switch (783864) | more than 6 years ago | (#22815390)

that are icy on the outside and warm and liquid inside, providing potential habitats.

Re:Exciting. (0)

Anonymous Coward | more than 6 years ago | (#22814764)

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.

But more importantly, life once existed by our current understanding of molecular biology. That methane didn't create itself.

---
Posted anon - lately I have had a --mod monkey on my back

Re:Exciting. (1)

AoT (107216) | more than 6 years ago | (#22815268)

No, there's methane on Mars that isn't necessarily organic in origin [sciencedaily.com] .

Oops (1)

AoT (107216) | more than 6 years ago | (#22815362)

I meant biotic in origin.

Re:Exciting. (1)

regiegnahtanoj (1183907) | more than 6 years ago | (#22815624)

I suppose at the very least we can still make fart jokes with them.

Re:Exciting. (1)

wxjones (721556) | more than 6 years ago | (#22815088)

This is a great example of the science that can be performed with unmanned probes. Too bad we are wasting most of our space research money on keeping a few humans alive in low-earth orbit.

Have a look at "Slow Life", Hugo 2003 winner (2, Informative)

mrcgran (1002503) | more than 6 years ago | (#22815544)

You might like to have a look at "Slow Life", by Michael Swanwick.
http://www.analogsf.com/Hugos/slowlife.shtml [analogsf.com]

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 [nicholaswhyte.info]
http://www.locusmag.com/SFAwards/Db/Hugo2003.html#nvt [locusmag.com]

"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."

Re:Have a look at "Slow Life", Hugo 2003 winner (0)

Anonymous Coward | more than 6 years ago | (#22815740)

this quote from the story is better: "Brace yourself. We've got a real ocean! Not this tiny little two-hundred-by-fifty-miles glorified lake we've been calling a sea, but a genuine ocean! Sonar readings show that what we see is just an evaporation pan atop a thirty-kilometer-thick cap of ice. The real ocean lies underneath, two hundred kilometers deep."

prescient, isn't it?

Re:Have a look at "Slow Life", Hugo 2003 winner (1)

DerekLyons (302214) | more than 6 years ago | (#22816856)

"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."

As usual, telling half the truth - a pretty important half. In both those places, life (as we understand it, which the life found was) cannot evolve, the conditions are too extreme. The life found there almost certainly evolved somewhere else and then adapted to those extreme environments.

Re:Have a look at "Slow Life", Hugo 2003 winner (0)

Anonymous Coward | more than 6 years ago | (#22817400)

well, at least some evolutionary biologists think that the bacteria around deep sea vents ("black smokers") were the first that evolved, that at one point in earth's history ALL living things generated their energy from chemical energy and that photosynthesis only entered the equation later on.
See William Martin & Michael J. Russell: On the origins of cells: a hypothesis for the evolutionary transitions from abiotic geochemistry to chemoautotrophic prokaryotes, and from prokaryotes to nucleated cells", in: Philosophical Transactions of the Royal Society. Biological Sciences 358 (1429), 2003, S. 59-85.

Re:Have a look at "Slow Life", Hugo 2003 winner (1)

MichaelSmith (789609) | more than 6 years ago | (#22818336)

"Is there life on Titan? Probably not. It's cold down there! 94 Kelvin

Another way of putting it is that it is only twice as cold as the coldest place on Earth. Given nuclear power I think humans could live on Titan quite easily.

I wonder if it has fossil oxygen or nitrogen dioxide? If such a thing could be found it might be possible to survive without uranium.

Re:Exciting. (1)

PPH (736903) | more than 6 years ago | (#22816156)

Titan is one of the most exciting bodies in our solar system.

What about Jessica Alba?

Your nerd credentials are hearby revoked.

life on/around gas giants (5, Interesting)

sveard (1076275) | more than 6 years ago | (#22814110)

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.

Re:life on/around gas giants (2, Informative)

clem (5683) | more than 6 years ago | (#22814324)

I believe that a gas giant's intense gravitational field can heat the cores of nearby moons.

Re:life on/around gas giants (1)

MorpheousMarty (1094907) | more than 6 years ago | (#22815314)

If you were the size of a moon, the pressure you feel on the side you face your planet will be different from the pressure on the far side. Add to this an elliptical orbit around a planet and the core of the moon has enough activity to churn and produce heat. A lot of things are pretty crazy once you're the size of a moon.

Re:life on/around gas giants (-1, Flamebait)

nawcom (941663) | more than 6 years ago | (#22814382)

Know-how response:

It's fart-man's home location in our solar system.

So -
a) there is life on the damn moon.
b) The race that fart-man originates from are a cave dwelling race. Heat from inside the moon is generated by the enormous volume of methane extracted from the asses of the cave dwelling race, hence the temperatures differ greatly compared to outside. Internal dynamics can be possible, due to the chance of the sound waves coming from the fart-man race, collectively, being amplified because of the acoustics set up inside the caverns of that ass-of-moon. This is the actual origin of the moon that revolves around the earth being referred to as "green cheese."

IMHO, that was a dumb question to ask. don't you ever read wikipedia, or are you one of those fundies who refer to a 2 millennium old collection of books with hogwash written in it from cover to cover? geez. go have a gas believing what you please.

(honestly, I am just bored so i felt like writing BS. I understand if my /.karma deserves a beating...)

Re:life on/around gas giants (1)

sveard (1076275) | more than 6 years ago | (#22814452)

I'm more into social sciences (yeah flame me for that too). I had no idea I had to have read this on wikipedia. Also, I'm an atheist.

And I've got the moral highground in this "discussion". ;)

Re:life on/around gas giants (4, Informative)

mollymoo (202721) | more than 6 years ago | (#22814416)

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.

The gravitational attraction between the moon and its parent planet is sufficiently strong that the modest changes in distance (and thus gravity) as the moon orbits are sufficient to repeatedly distort it by a 'significant' amount, which generates heat. It's kinda like a squash ball, which gets warm as it is repeatedly compressed during play.

Re:life on/around gas giants (4, Informative)

Deadstick (535032) | more than 6 years ago | (#22814638)

This is the same process that keeps one side of the Moon facing the Earth, and one side of Mercury facing the Sun. Both of them had some amount of spin long ago, but the squishing removes energy, and the only place that energy can come from is the rotational energy of the spin.

The strength of the effect depends on the relative sizes of the two bodies, and the radius of the orbit, which is why most of the bodies in the solar system aren't tide-locked.

rj

Re:life on/around gas giants (4, Interesting)

isomeme (177414) | more than 6 years ago | (#22815598)

Mercury isn't 1:1 locked (one face always toward the sun). Rather, it's 3:2 locked (three rotations for every two revolutions around the sun). Thus, all of the surface gets periods of sunlight and darkness.

The 3:2 resonance combined with Mercury's eccentric orbit does produce some interesting effects. As seen from certain points on the surface, you could start out in night, watch the sun rise, move a little way up the sky, turn around, set near where it rose, and then later rise again with a noticeably larger apparent diameter and travel all the way across the sky, then set, rise near where it set but now looking smaller again, turn around, and set again.

Re:life on/around gas giants (1)

Deadstick (535032) | more than 6 years ago | (#22815960)

Aha, looks as if I'm 43 years out of date on Mercury...apparently that was determined in 1965. Thanks for the correction.

rj

Re:life on/around gas giants (1)

MichaelSmith (789609) | more than 6 years ago | (#22818168)

The really strange thing is that for a while it appeared that the rotation of Mercury was locked on Earth. We were just unlucky that the same face was pointing to Earth on every close approach.

Re:life on/around gas giants (0)

Anonymous Coward | more than 6 years ago | (#22815614)

one side of Mercury facing the Sun
Common mistake, from Wiki [wikipedia.org] :
radar observations in 1965 proved that the planet has a 3:2 spin-orbit resonance, rotating three times for every two revolutions around the Sun; the eccentricity of Mercury's orbit makes this resonance stable--at perihelion, when the solar tide is strongest, the Sun is nearly still in Mercury's sky. The original reason astronomers thought it was synchronously locked was that whenever Mercury was best placed for observation, it was always at the same point in its 3:2 resonance, hence showing the same face.

Re:life on/around gas giants (1)

Nazlfrag (1035012) | more than 6 years ago | (#22816142)

Mercury facing the Sun
Nitpick, it's locked into a 3:2 rotation. Here's the relevant wikithingy [wikipedia.org]

Until radar observations in 1965 proved otherwise, it was thought that Mercury was tidally locked with the Sun. Instead, it turned out that Mercury has a 3:2 spin-orbit resonance, rotating three times for every two revolutions around the Sun; the eccentricity of Mercury's orbit makes this resonance stable. The original reason astronomers thought it was tidally locked was because whenever Mercury was best placed for observation, it was always at the same point in its 3:2 resonance, so showing the same face, which would be also the case if it were totally locked.

Re:life on/around gas giants (1)

Deadstick (535032) | more than 6 years ago | (#22820172)

Yes, isomeme updated me on that. That condition means that Mercury is still dissipating spin energy, so I suppose it should eventually achieve 1:1 lock, even with the orbit eccentricity trying to keep it stable.

rj

Re:life on/around gas giants (2, Informative)

Caractacus Potts (74726) | more than 6 years ago | (#22814544)

Tidal forces are kneading these planets like bread. There's a pretty good about of mechanical forces getting turned into heat.

Re:life on/around gas giants (0)

Anonymous Coward | more than 6 years ago | (#22814622)

Someone already explained that tidal forces from the gas giants due to surface features and elliptical orbits cause the solid cores to heat up. Pressure can also melt ice, as liquid water is denser then water ice. As for radiation, the kilometers thick crust is far more then enough to reduce the planet's radiation to less then the background from decaying protons.

Re:life on/around gas giants (1)

Muad'Dave (255648) | more than 6 years ago | (#22818042)

...from decaying protons.


Slightly OT, but has anyone actually observed a decaying proton? Wikipedia says no [wikipedia.org] .

Re:life on/around gas giants (1)

Nerrd (1094283) | more than 6 years ago | (#22815092)

What about radiation? we still don't know where all the heat comes from that our planet generates internally, but one of the things that generates it is radioactive decay.

Pardon the lame article...

http://www.newscientist.com/article.ns?id=mg18725103.700 [newscientist.com]

Re:life on/around gas giants (1)

Tablizer (95088) | more than 6 years ago | (#22815720)

Life ON gas giants seems like a big NO with what we currently know about the conditions required for life to emerge.

But because gas giants are gravity wells, they'll suck in life blasted from the surface of smaller bodies. Even though life may not start in gas giants, they can be conducive to any arrivals because temperature gets warmer the deeper you go in. Thus, they have a sweet spot as far as temperature. They just need some water, which gas giants seem to posses, but not in large doses.
     

not so: consider this (1, Interesting)

Anonymous Coward | more than 6 years ago | (#22816246)

Life ON gas giants seems like a big NO with what we currently know about the conditions required for life to emerge.
This is not so. The physical and chemical processes on the local gas giants are indeed compatible with current theories of the genesis of life on Earth.

There are so many hydrocarbons observed in the universe outside Earth that we haven't even identified all we've discovered. The environment of Earth in its early history was chemically much like that of the present-day gas giants: reducing. This is a critical point because it allows hydrocarbon synthesis and re-synthesis. Self-replicating molecules can, in theory, be very simple compared to what you probably referred to hand-wavingly as "life" just now. Sagan (along with others, IIRC) proposed "floaters" and "hunters" as entirely viable, but hypothetical forms of life viable on a gas giant such as Jupiter. These represent complex multicellular life and not Archaea-like single-celled life, which would be more likely, let alone simpler self-replicating biopolymers like DNA or RNA, or perhaps something more exotic.

Earth's present environment (for the last 2.5-3 billion years) has been oxidizing rather rather than reducing, due (per current theory) to the average thermal speed of light molecules exceeding that of local gravity (we know this is the case, but of course we have to take an educated guess that it's actually the cause and not simply a true but irrelevant consequence of physical laws).

The problem is not so much that even the ancestor of Life As We Know It is impossible on gas giants, but rather our inability to determine the likelihood of life arising in an environment given an environment capable of sustaining life. In the language of the Drake Equation, we know Ne poorly is irrelevant because we know it's at least as big as Fl and we think that Fl is probably much less than 1 (i.e. life doesn't always arise even when conditions are suitable to sustain it).

It's not so impossible that there is life on gas giants, even if it is improbable in the minds of some very different life forms from a very different environment.

Re:life on/around gas giants (1)

cybrthng (22291) | more than 6 years ago | (#22818594)

Carl Sagan did some fantastic conceptions of life forms on gaseous giants such as living organisms that float like balloons in the upper atmospheres and feed off the biological matter floating around or like plants consume carbon dioxide and use the limited light of the upper atmosphere to create there own energy.

Fascinating stuff to conceptualize life were we don't think it would exist. After we found it in the deepest/darkest places of our own earth we soon realized its terribly short sighted to limit life to what we see.

Re:life on/around gas giants (1)

htwf_and_ip (1248696) | more than 6 years ago | (#22825698)

why are these moons hot on the inside

That's no moon....

icy on the outside and *icy* and liquid inside (1, Interesting)

Cordath (581672) | more than 6 years ago | (#22814118)

Don't forget that the melting point of water *decreases* as pressure increases. The liquid core may well be damned cold!

Re:icy on the outside and *icy* and liquid inside (5, Informative)

Jabba_the_Butt (312104) | more than 6 years ago | (#22814224)

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 [lsbu.ac.uk] .

Re:icy on the outside and *icy* and liquid inside (1)

scottrocket (1065416) | more than 6 years ago | (#22814490)

Or, being Titan it may not be water, but perhaps a slushy hydrocarbon mix. Ganymede may be a better candidate for a water ocean (we won't know til we go there-hint hint to NASA/gov/short-sighted bureacrats!).

Re:icy on the outside and *icy* and liquid inside (1)

Tranzistors (1180307) | more than 6 years ago | (#22814294)

So? The problem with ice is that it damages cells. In this environment living is harder than in warm water, but still much nicer than in crystal one.

Fluid interior does not mean warm. (5, Interesting)

Jabba_the_Butt (312104) | more than 6 years ago | (#22814172)

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.

Re:Fluid interior does not mean warm. (1)

tirerim (1108567) | more than 6 years ago | (#22814428)

Warm or hot, probably not. Capable of supporting life, who knows? Given the kinds of extremophiles we know about on Earth, it's still possible that life could exist even at such low temperatures. But there's no way to know for sure until we send a probe to the surface, and I don't think there are current plans for one.

Re:Fluid interior does not mean warm. (1)

Kandenshi (832555) | more than 6 years ago | (#22814730)

Supporting life seems fairly easy. As you say, there are extremophiles right here that might be able to make a go in rather unpleasant (to most life) environments.

The bigger question IMO is if life could readily start in such environments. I suppose it's short sighted of me, but I'd always thought of life originating in relatively normal environments and then migrating to those really hot/cold/acidic/basic/whatever places. Perhaps life can live on Titan/Ganymede, but would it need to be transplanted life from Earth?

Re:Fluid interior does not mean warm. (1)

AoT (107216) | more than 6 years ago | (#22815322)

The problem is that normal is relative, in this case to our biology, generally. I we had evolved in another environment, that would be normal. We simply lack the information to know what environments life can start in.

Re:Fluid interior does not mean warm. (1)

tirerim (1108567) | more than 6 years ago | (#22815502)

And for that matter, life didn't evolve on our own planet in exactly what we now think of as a normal environment, one notable difference being that there was pretty much no molecular oxygen in the atmosphere.

potential habitats? (1)

rice_burners_suck (243660) | more than 6 years ago | (#22814196)

providing potential habitats? This is a confusing statement. Do they mean potential habitats for life that might be hiding in there currently, or potential habitats for humans who might travel there in the future? And would these habitats actually need to be inside a hollow underwater dome beneath the icy surface? This sounds cool actually.

Titan == Darius? (0)

Anonymous Coward | more than 6 years ago | (#22814198)

If there are oceans, there may just be enough space to sustain alien marine lives for future astronauts driving fast approaching giant battleships to dig up some King and Queen Fossils, and Great Things will happen.

in other news... (1)

ILuvRamen (1026668) | more than 6 years ago | (#22814216)

And on the Titan internet's #1 news for nerds website, dot slash, they're posting about how there may be oceans on Earth :P Btw this is good cuz now astronaughts can go swimming cuz you know how they're always saying it's hard to get enough exercise in space with no gravity.

Re:in other news... (-1, Troll)

nawcom (941663) | more than 6 years ago | (#22814282)

I am intrigued by your ideas and wish to subscribe to your newsletter. DISREGARD THAT I SUCK TITAN COCKS

He just missed the news! (4, Interesting)

aktzin (882293) | more than 6 years ago | (#22814244)

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 years

Re:He just missed the news! (1)

AoT (107216) | more than 6 years ago | (#22815436)

to have his suspicions confirmed like this.

Nothing against Clarke, but wrong moon.

Re:He just missed the news! (1)

rossdee (243626) | more than 6 years ago | (#22815910)

2001 wasn't the only book ACC wrote you know. He also wrote articlea for science magazines, and I think Titan was mentioned there.

Re:He just missed the news! (1)

K. S. Kyosuke (729550) | more than 6 years ago | (#22817352)

Huh? Maybe you just need to get out of the basement, go to the library and fetch a copy of Imperial Earth [wikipedia.org] ?

Welcome (0, Offtopic)

Mike Kelly (864224) | more than 6 years ago | (#22814268)

I, for one, welcome our Titan Overlords!

Couldn't we send a rover? (1)

g253 (855070) | more than 6 years ago | (#22814284)

Okay, I have a (dumb?) question for the rocket scientists here : since we have this nice rover design that we know works well on Mars, wouldn't it be interesting to send one on Titan to take a closer look?

I mean I know it's a hell of a lot farther than Mars, but could anyone explain what are the biggest obstacles? Is it cost, accuracy, surface conditions, difficulties for reliable communication... ?

Forgive my wild enthusiasm, but this is all very interesting and I either want us to send robots there or to know why we can't :)

Re:Couldn't we send a rover? (3, Insightful)

tirerim (1108567) | more than 6 years ago | (#22814392)

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.

Re:Couldn't we send a rover? (1)

rbanffy (584143) | more than 6 years ago | (#22821380)

"will take an entirely new design."

Not entirely new. The biggest problem seems to be, by far, the power source (for both general operations and communications).

Landing is easier with a thick atmosphere. Temperature seems stabler than on Mars - a thick atmosphere supposedly helps with that too. The fact it rains could help with dust if there is any (but it could pose a problem to any rubber seals). The communications problem could be partly solved with an orbiting relay that could, in itself, do some studies from orbit - with it, the rover could have a lower power high-bandwidth link with the orbiter. It would be useful to be able to communicate directly with Earth in case something goes wrong with the orbiter part, even if with lower bandwidth. More smarts in the rover itself could make up for the added comm delay.

Other kinds of challenge arise from the environment being far more dynamic than Mars. When mountains move a couple miles in months, that's because the ground is less grounded than usual. I suspect the life expectancy of any surface structures (that could include rovers) in such environment is much shorter than on less interesting places. I would not expect a nuclear-powered Huygens-like probe to last a couple months there before being crushed by a very quick mountain.

Perhaps, instead of a rover, a long-life balloon could be designed to float just above the surface but, then, that would be your entirely new design.

Re:Couldn't we send a rover? (0)

Anonymous Coward | more than 6 years ago | (#22814418)

Uhm, we already did send a robot there. Its name was Huygens and it landed in 2005. A rover would be a bit more difficult, because of the temperature, lack of solar power, difficulty of communication, and generally unknown surface conditions. The Huygens lander only had enough battery power to keep transmitting for a few hours after it was released, so most of its data came from descent and only a small part from the surface.

http://en.wikipedia.org/wiki/Huygens_probe [wikipedia.org]

Solar power (1)

SideshowBob (82333) | more than 6 years ago | (#22814442)

The Mars rover is solar powered. Titan is too far from the Sun to make that practical. So while a rover could be sent, it would have to be significantly different from the current designs.

Re:Couldn't we send a rover? (1)

flyingfsck (986395) | more than 6 years ago | (#22814606)

Hmmm, it will sure make a big splash...

Re:Couldn't we send a rover? (0)

Anonymous Coward | more than 6 years ago | (#22823106)

Actually, not really a dumb question. You got most of the obstacles yourself. I think a big one is communication. Saturn is about 5 times as far away as Mars. It also has a 16 earth-day rotation, meaning any surface mission has to operate on its own for 8 day stretches while it faces away from earth. Furthermore, even the Mars rovers only get good data rates when routing through one of the Mars orbiters, instead of direct to earth.

Also, a rover would not be a good move at the moment. Titan appears to have a great deal of liquid (mostly methane and ethane on it's surface). Scientists aren't 100% sure that's what the flat spots on their radar images are, but it's a pretty good bet. Unless you know exactly what's where, any lander has to be able to float as well as survive a land landing. IIRC, the Huygens team thinks that robot landed in some soft sand or methane mud.

I think a more likely mission would be either a dedicated Titan orbiter (which is not an easy orbit to get into, however) with a really good radar and infrared camera to probe the clouds, or perhaps an atmospheric flying mission. The atmosphere of Titan is extremely well suited for it, being much denser than earths. A mission could utilize either a balloon, or possibly even a radioisotope thermal generator-powered aircraft that deploys from its heatshield in midair.

However, Cassini isn't done with her mission yet, and nothing is expected to changed drastically on Titan for the foreseeable future, so there's little rush to get there. It's likely that the next Saturn mission will launch sometime in the next 10-20 years.

Don't you just hate it... (1)

Starteck81 (917280) | more than 6 years ago | (#22814310)

...when you can't remember where you left your geographical features?

Crunchy on the outside . . . (0)

Anonymous Coward | more than 6 years ago | (#22814538)

chewy on the inside.

cadbury egg? (1)

Eun-HjZjiNeD (1001079) | more than 6 years ago | (#22814542)

"icy on the outside and warm and liquid inside"

Anybody else think of cadbury eggs when they read this?

Re:cadbury egg? (1)

Himring (646324) | more than 6 years ago | (#22814676)

reminds me more of my ex....

Let's Just Stay in onight...and forever. (4, Funny)

TheLazySci-FiAuthor (1089561) | more than 6 years ago | (#22814564)

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 [wikipedia.org] 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!

Re:Let's Just Stay in onight...and forever. (1)

rbanffy (584143) | more than 6 years ago | (#22821436)

"Maybe out planet, with it's skin lain bare to the cosmos, is an exception for a life-harboring world."

That sounds very likely. Life on Earth depends on many things that seem to be rare - a strong magnetic field that protects us from our own sun, just right temperature - so that there is liquid water - just right atmosphere - so that there is no runaway greenhouse effect like Venus - and so on. With all the mass extinctions that happened here before we came, we could consider ourselves to be an extremely lucky race.

Because if we weren't so lucky, there would be nobody wondering how lucky we are.

Sounds familiar (1)

Tablizer (95088) | more than 6 years ago | (#22814620)

They found that the features had shifted from their expected positions by up to 30 kilometers.

Are they sure it's not just another metric-english-units screwup?
     

So what? (1)

Prius (1170883) | more than 6 years ago | (#22814908)

So what if Titan has an ocean for a mantle. That doesn't mean it could be a better habitat for humans. At least in the short term, anyway. The crust is hundreds of kilometers thick on Titan. We can't drill that deep on Earth, where we can carry huge things around. If we wanted to get the water out of Titan, or Ganymede or Enceladus or Europa or any other water-filled moon, for that matter, we'd need to bring huge drills that weigh millions of kilograms; given our present technology, that is impossible, technologically, logistically, and economically. That doesn't mean Titan isn't a lucrative place to colonize; it's entire surface composition is very rich in potential rocket fuel. Once we establish an infrastructure on to harvest methane from its atmosphere or scoop stuff out of its seas and lakes, it would take half of the problem out of colonizing the outer solar system. But we'd still need to build an extremely expensive infrastructure, first.

Re:So what? (1)

ArcherB (796902) | more than 6 years ago | (#22817744)

So what if Titan has an ocean for a mantle. That doesn't mean it could be a better habitat for humans. At least in the short term, anyway. The crust is hundreds of kilometers thick on Titan. We can't drill that deep on Earth, where we can carry huge things around. If we wanted to get the water out of Titan, or Ganymede or Enceladus or Europa or any other water-filled moon, for that matter, we'd need to bring huge drills that weigh millions of kilograms; given our present technology, that is impossible, technologically, logistically, and economically. That doesn't mean Titan isn't a lucrative place to colonize; it's entire surface composition is very rich in potential rocket fuel. Once we establish an infrastructure on to harvest methane from its atmosphere or scoop stuff out of its seas and lakes, it would take half of the problem out of colonizing the outer solar system. But we'd still need to build an extremely expensive infrastructure, first.
While I'm not very familiar with Titan, I know that Europa is constantly churning, with cracks opening up and being resealed again by water rising to the surface to freeze again, forming a new ice shell. It seems to me that all we would need to do is land a probe wherever there is "new" crust (ice) and sample the water there. We might be able to actually get a probe into the under-ocean one day, but for now, I think this would be the best approach. Then again, IANARSoNE (...Rocket Scientist or NASA Employee)

Re:So what? (1)

kevin.fowler (915964) | more than 6 years ago | (#22817774)

And also not get fried by large amounts of radiation.

Science and Science Fiction (0, Offtopic)

Simonetta (207550) | more than 6 years ago | (#22816050)

I really liked Arthur C. Clark's works. I liked 'Songs of a Distant Earth' the best. The 2001,2010,2060,3001 series was fantastic.

    But it was science fiction. It will never be true, not the alien intelligence, not HAL, not monoliths on the moon, and especially not human travel to distant planets. Don't mod me down or call me a Luddite, but it's just not going to happen.

    Guys, these are not distant points on the Earth like Antarctica or some other place that you can climb into to a machine, fill it with fuel and just go to. These are dots in the night sky. They are millions of miles away. And there is nothing there that can justify the unbelievably large public expense and the near-certain failure of such a journey. The prospect of increasing quote unquote scientific knowledge just doesn't cut it anymore.

    Guess what! We're broke! We pissed away all the funds that you would have liked to have spent on space travel on wars, debt service, and bail-outs for sub-prime mortgage banks. Remember the senator who said fifty years ago, "A billion here, a billion there, soon you start talking about real money!". Well we spent a hundred billion here and a hundred billion there, lost a few hundred billion here and there and didn't log in a few hundred billion over the years on account of secret 'black box' projects. And now we're broke.

    Not only are we broke, but we are facing climate change, overpopulation (and its endless expensive wars), and economic meltdown. The US dollar lost 50% of its value next to the world's second major currency (the euro) in less than five years. Housing prices are falling 5% a quarter, food costs are rising 10-20% a year, oil is over $100 a barrel, and gold is over $1000 an ounce. And we're broke, and deeply in debt on all levels.

    Gentlemen, we must accept the finality of reality after having expired all the other options. There isn't going to be any manned space travel program to other planets. There is unlikely to be any more trips to the moon.

    It was great, it was fun, it fired the imagination of generations. But it's over.

    At least we still have Star Trek reruns.

    Again, don't mod me down for pointing out the reality of our current situation. It is real and the space program no longer is.

    Thank you. Damn. Slashdaughters are the toughest audience to explain this to. Go put your brains into solving some real problems. Forget space exploration.

Re:Science and Science Fiction (2, Insightful)

argent (18001) | more than 6 years ago | (#22818444)

Science fiction: 2001, Star Trek, Lost in Space, ...

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.

An ocean of pee? (1)

4D6963 (933028) | more than 6 years ago | (#22823702)

"We believe that about 100 kilometers (62 miles) beneath the ice and organic-rich surface is an internal ocean of liquid water mixed with ammonia,"

Liquid water mixed with ammonia? Sounds like pee to me! An ocean of pee, with an organic icy crust floating on top of it, the whole surrounded by an atmosphere of methane... This place sounds awfully much like the toilets of the solar system.

I don't think I want to know what the core is made of..

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