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Space

Continents on Titan? 36

Posted by michael from the LGM-or-BEMs? dept.
Saint Aardvark writes: "CNN reports here that a second bright spot has been found on Titan. The speculation is that it's a continent, but scientists can't be sure until Cassini arrives at Saturn and drops the Huygens probe through the atmosphere."
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Continents on Titan? More

Continents on Titan?

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  • Sierra Club and Greenpeace will go off on the Administration of whatever President would suggest mining it for raw materials.

  • hmm (Score:1)

    by Voxol ( 32200 )
    I claim this land-afa-spain!

  • "snow" is solid precipitation (Score:4)

    by coyote-san ( 38515 ) on Sunday May 20, 2001 @07:20AM (#210604)
    "Snow," in this context, refers to solid precipitation out of the "atmosphere." That can refer to water ice on the surface the earth, iron flakes at the boundary of the inner and outer core, or hydrocarbons on the surface of Titan.

    Nowhere does the article claim that Titan has water snow - it says "hydrocarbon rain and snow". The "hydrocarbon" applies to both.
  • The ESA people built both the Huygens transmitter and the receiver for it on Cassini - and it is sad, but true, that they "forgot" to provide a means to compensate for the variable (?) Doppler shift. So there's simply not going to be any way to get the full bandwidth of data back from Cassini.

    I was talking to a member of the orbit planning committee (yeah, these things get done in the mother of all committees) and she said, right now, the US groups are going ahead with planning as if there is no problem. It's ESA's baby and ESA's fault, so they can deal with it...

    Unfortunately, the only way to "deal with it" and get data volumes greater than zero is to (a) reduce transmitted data (low bandwidth) and repeat it all over the band, and (b) do fancy moves with velocity component matching between Huygens and Cassini - completely outside the spec.

    Add to this, Cassini is the size of a bus, and a fixed platform - so phoning home requires all (or most) instruments to stop looking, and the instruments look in mutually exclusive directions. Fights over orbit planning are predicted to come to blows easily this time.

    But hey, we can do Faster Cheaper Better (pick two) missions now - they carry very few instruments and none are worth fighting over, see? There's progress for you.

  • Sadly, the press (and the public?) love to dissect the failures more than they love to laud the successes, so from the PR perspective (and only from that perspective) Faster Cheaper Better has been a failure.

    That was precisely my viewpoint too, until I heard out one of the profs in our department (he ran the CONTOUR mission, FWIW). His point was this: we have lots of Mars data, but even now, our best non-sexy data (e.g. the atmospheric composition) comes from the Vikings (1970s). Yes, the Mars Orbiter and the Sojourner Rover provided gorgeous pictures, and some useful science data too, but there were too many compromises built into the mission due to weight/fuel/cost constraints to do really comprehensive science.

    OTOH, I agree with you that some science is better than none at all: when the billion dollar Mars Orbiter vanished, that was a lot of time and effort with nothing left to show. So the concept of F/B/C is, indeed, good. And I agree with you that the American public is way too risk intolerant (try swimming in a public place!), and the media loves failure (compare Apollo 12 coverage to Apollo 13).

    But: the pendulum has swung too far. The missions now are too fast, too cheap, and better only from the pretty-picture perspective. We're building not one, but two identical Athena rovers for Mars - and you know what? The best science can't make it there, due to weight and payload volume limitations. This is not good science.

    Of course, I personally do radio astronomy, and all this is corridor gossip, so feel free to add salt to taste...

  • Weather _never_ reaches an equilibrium, or steady state condition. There are several variables, all linked to divergent forces.

    1 - Gravitational contraction. The sheer pressure of matter crushing into the center of a planet or moon generates heat. This continual heat dissipation through the core and outer layers leads to convection in the core and heats the atmosphere. Heating of the atmosphere causes convection, like a pot of boiling soup, but at a much much colder temperature.

    2 - Light the from Sun. The Sun is immensely powerful and yes, does heat Titan, even from that distance.

    3 - Gravitational interactions with Saturn. Saturns gravity distorts its moons as they orbit, causing techtonic activity. Titan would also have gravitational interactions from the other moons.

    4 - Coriolis effect. This is the kicker. Since Titan is spinning, a small perterbation in the pressure in one part of the atmosphere causes the gases rushing in to balance the pressure to swirl because gas near the equator is moving faster than that at the poles. This is the base force for weather on earth and all bodies with an atmosphere.

    5 - Dust and rocks. Titan, like all bodies in the solar system, is continually showered with dust and rocks of all sizes. These all cause perterbations in the atmosphere, and since these forces are so divergent, they affect the entire atmosphere.

  • Bright spot explained (Score:3)

    by Ukab the Great ( 87152 ) on Sunday May 20, 2001 @02:27AM (#210608)
    http://slashdot.org/articles/01/05/03/1617211.shtm l

    Guess where Dell put all those recalled laptops that catch on fire...
  • I don't understand this conslustion that if a planet has water it will have life. I know all living things need water. But it doesn't mean it's going to have some type of primative lifeform.

    The other conclustion is that it won't be anything more then really primative organisms, I bet if the moon has life it's filled with tall green men that where robes and large head sets.

    -Jon
  • From the article:
    ..which will then parachute through the atmosphere and presumably land several hours later.
    I'm not entirely sure if this is a dig at NASA's recent space upsets, or just someone unsure about the effects of gravity..

  • Titan's no good for the base. They have to put it on Phoebus to conform with the historical documents I found that came with my first copy of Doom. It's all in black and white. The demons spawned on Phoebus, not Titan.

  • Considering NASA's woeful recent record of building a lander for Mars, a much easier task engineering-wise, let us hope they manage it right this time. Imagine the repercussions for NASA and the waste of time and money involved if they suffer another lander failure...

    Still hoping for Pluto Express ...

    -michel-

  • Couple of issues:

    Last I'd heard, Titan has 1.5 atomspheres, not 10.

    There's still energy being imparted to Titan, ensuring the lack of a steady state. First is the Sun -- while it's only 0.01% of the energy Earth receives, it's still energy. The other source would be tidal forces from Saturn. (See Io as a prime example of what tides can do.) Now, I'm speaking off the cuff here, but I'd be willing to bet that a moon Titan's size circling a gas giant is going to see a lot of tidal deformation...which is going to impart heat through the mechanical action on the planet's surface/crust...


    ----------------------------------------
    Yo soy El Fontosaurus Grande!
  • what? what does 'pre-op TS' mean? I get the feeling you're insulting me. But if you are, I'm sure you'd want me to actualy understand what you said.

    Rate me [picture-rate.com] on picture-rate.com
  • "But: the pendulum has swung too far. The missions now are too fast, too cheap, and better only from the pretty-picture perspective."

    huh? thats just plain false. don't buy into the "they don't make em like they used to" type empty arguments coming from impossible to please curmudgeons and so called critics of space science. Some obvious examples that fly in the face of your claim are the Mars Global Surveyor (part of NASAs faster better cheaper program) which has collected more information about Mars than all previous missions combined. The F.B.Cheaper Transition Region and Coronal Explorer probe (75M$!) is now finally helping to uncover the mystery of why the suns corona is so hot. Something not even SOHO has accomplished. The spectacularly successful Near Earth Asteroid Rendezvous (NEAR)probe was the first spacecraft ever to orbit an asteroid and take close up images of its surface. It was the first to land on and take (extremely accurate) close range gamma spectroscopic measurments of an asteroids' composition. It provided invaluable scientific information on the inner morphology of the asteroid which gives insights into the structure of other old large asteroids (and potential NEO's). Mars Pathfinder, another member of the faster better cheaper brigade did not just take "pretty pictures", it gathered huge amounts of info on mineralogy and geochemical processes on the surface using the APXS instrument on the sojourner rover. It also sent back never before seen meterological measurments. Even if a mars mission only did send back images of the surface they would be scientifically valuable, not to mention the huge public interest they gather.

  • Wow, that is absolutely the best pre-op TS I have ever seen. Except for the slight "shadow" you refer to, you look 97% like a real girl!

    And this is on topic how? Oh, I get it...Nice continents on Titan, heh-heh-heh...

  • Since Titan is larger than the moon but maybe half the diameter of Earth, the surface gravity should be about 1/4 to 1/3 that of earth (a wild guess). With an atmosphere, it is probably just a matter of temperature if anyone is home. The other thing is that, being farther out in the solar system, it probably doesn't get the protection we do of larger planets to suck in asteroids that might otherwise hit us. They probably get hit more often.

    Although there might be enough resources otherwise for a mining operation. It could be relatively easy to pull oxegen from the atmosphere, etc if someone wanted to put a base there.

    I figure that we'll be out there in maybe 300 - 400 years. This based on the idea that it took maybe 500 years to get the New world under total control, and so I project another time period of similar size (500 to 1000 years) to expand out across the Solar System

    Check out the Vinny the Vampire [eplugz.com] comic strip

  • Just as I find another great vacation spot to "get away from it all" slashdot has to rat me out with the help of Nasa. Now the tourists will come and ruin it for all of us! Dammit why can't I have something of my own for once!
  • According to the article, this is the second bright feature to be found on Titan with the new optical system employed. The image accompanying the article really does seem to clearly show this apparent land mass or continent, however there is no evidence of the first bright feature. Presumeably this is on the other side of the moon. It would be interesting to note where the two apparent masses are in relation to eachother- if they are directly opposite this might lead to a different explanation of their existence than if they were apparently randomly occuring.
  • If previous space missions are anything to go by.......... and the probe won't work Conclusions will be: If Huygens makes a splash on impact - it's an ocean If Huygens explodes with no splash - it's a continent
  • James Hogan wrote a really good book about "life" on Titan. It focusses a lot on the fact that Titan's atmosphere and temp. are near the tripoint of methane; much like water here on Earth. It is a good and funny read. You can find it here. http://www.amazon.com/exec/obidos/ASIN/0785787631/ o/qid=990374011/sr=8-1/ref=aps_sr_b_1_1/002-130796 0-9176821
  • It might be possible for life to exist without water, given all the hydrocarbons, creatures might exist with highly flammable blood.

    Good thing it's cold there.

    No oxygen, no problem...

  • Re:According to the article.. (Score:3)

    by Soft ( 266615 ) on Sunday May 20, 2001 @01:50AM (#210623)
    One would think that after all this time, that the system (weather) on Titan should be more or less at a steady state condition.

    It could be snowing steadily? And there's still the change in sunlight every few weeks, as Titan revolves around Saturn...

    It is too cold on Titan to allow for liquid water so the snow couldn't melt.

    Wait, who said it would be water? It is supposed that various hydrocarbons `rain' or `snow' to the surface, definitely not water.

    It can't evaporate either since, according to scientists in the article, the atmosphere is 10 times thicker than here on earth. Snow isn't going to vaporize at 10atm.

    "Thicker" doesn't mean "higher pressure". IIRC the pressure on Titan would be around 1.5 atm; however, since it is much colder than on Earth and the atmosphere doesn't have the same composition, its density can very well be ten times as much as ours.

  • That is, if Cassini manages to listen to Huygens! (Score:4)

    by Soft ( 266615 ) on Sunday May 20, 2001 @01:31AM (#210624)
    Let's hope they figure out a solution to the design flaw that was discovered last year, that the radio receiver on Cassini won't be able to compensate for the Doppler shift [spaceflightnow.com] as Huygens rapidly changes speed in Titan's atmosphere...

    That could be bigger than the 1999 double Mars probe failure, Galileo's jammed antenna, or Hubble's nearsighted mirror!

  • Re:So does this mean there's life? (Score:5)

    by Soft ( 266615 ) on Sunday May 20, 2001 @03:09AM (#210625)
    First of all, as far as we know, Titan probably doesn't have any liquid water; it's too cold out there.

    I don't understand this conslustion that if a planet has water it will have life. I know all living things need water. But it doesn't mean it's going to have some type of primative lifeform.

    Very true. But we're looking for life anywhere we think it's likely to appear, and optimists think that it will evolve anywhere with the right conditions.

    Furthermore, I recall some crazy idea mentioned in Stephen Baxter's Titan, that life could exist there, based on nitrogen, ammonia and cyanide instead of oxygen, water and carbon dioxyde... Who knows? Not us, and that's why we're trying to get a look.

  • being farther out in the solar system, it probably doesn't get the protection we do of larger planets to suck in asteroids that might otherwise hit us.

    I am no expert in orbit calculations, but this sounds plausible to me. As Titan is on orbit around Saturn, any asteroid that Saturn catches could be a threat. The atmosphere of Titan is very thick, so it propably shields the surface (and base) against small meteorites.

    It could be relatively easy to pull oxegen from the atmosphere

    The atmosphere of Titan is mainly composed of nitrogen (more than 99 per cent) and methane (CH4) so it is not easy to get oxygen from the atmosphere. However, there should be some water ice on the surface.

    A bigger problem is energy - the temperature on Titan is around -170 C. Solar energy is useless. A theoretical maximum at the distance of Saturn is less than 20W per a square meter of solar panels, and the atmosphere is pretty thick. Also, there is propably not much silicon for making the Solar panels. In the outer Solar system, almost all elements heavier than oxygen are pretty rare.

    The best solution I can think of is a fusion reactor using deuterium extracted from the atmosphere.

    Titan is propably the best source of hydrocarbons in the Solar System, so I think we will go there some day. Some asteroids (carbon-condrite-type) contain also hydrocarbons, but I think Titan would provide a more steady supply of them.

  • This part I don't understand. Not only will it be extremely dark, it will also be extremely hazy. I'm sure that, regular optical photography wouldn't work. However, there was no mention of how they plan to take pictures once the probe penetrates the atmosphere.

    Now, I'm no expert on atmosphere... but, if the atmosphere on Titan is 'perfectly still' as they claim it to be, wouldn't that mean it would have to be very dense, right down to the surface?

    Oh well... I suppose, whatever they do find, should be interesting anyway.

  • It might be possible for life to exist without water, given all the hydrocarbons, creatures might exist with highly flammable blood.

    Good thing it's cold there.
    Or is that how they stay warm?
    (propane is a hydrocarbon)
  • Titan boasts an atmosphere, composed mostly of nitrogen and methane, ten times thicker than that on Earth. Scientists theorize that hydrocarbon rain and snow drizzle down to the surface.

    Hydorcarbons are the primary ingredients of gasoline and other petroleum products.

    No wonder research of this planet picks up during the Bush administration. He's opening it up for exploration.
  • Perhaps he should just shut the hell up and let someone with a passport take over, or even someone who knows where Europe is. (so that rules out most Americans ;))
  • of all the moons of jupiter only titan and (now) Europa have the capability to support any semalaence of life . What if we find life on titan? That would be huge! Even without that , it makes a colony that much easyer.
  • We're gonna crash the probe in to some alien nation and, if they're anything like us, cause them to go to war war with their biggest enemy. Because theres no way the machine from the could've come from Earth where they have nothing but water so any life but have trouble surviving without the abundant supply of liquid methane, like on Titan.
  • But hey, we can do Faster Cheaper Better (pick two) missions now - they carry very few instruments and none are worth fighting over, see? There's progress for you.

    "Faster Cheaper Better" has gotten a bum rap. The whole point of the program was that some missions would fail but that, rather than bundling them so that the failure of one jeopardize the lot, the failures would be relatively inconsequential. Thus less time/money/effort would be waisted trying to prefect each component, and many more successes could be had for the same budget. Yes, there would be more failures, but that shouldn't matter to anyone; the goal is more successes for less money.

    Sadly, the press (and the public?) love to dissect the failures more than they love to laud the successes, so from the PR perspective (and only from that perspective) Faster Cheaper Better has been a failure.

    -- MarkusQ

  • From the article: ..which will then parachute through the atmosphere and presumably land several hours later. I'm not entirely sure if this is a dig at NASA's recent space upsets, or just someone unsure about the effects of gravity...

    (*smile*) In the context, I suspect the quibble is that it can't "land" if there's no "land" on which to, well, land--it might "ocean" instead.

    -- MarkusQ

  • According to the article.. (Score:3)

    by Freija Crescent ( 452135 ) on Sunday May 20, 2001 @01:29AM (#210635) Homepage Journal
    It might be snowing on that planet. This brings up two interesting points.

    Firstly, where did i put my ski equipment? I think there are some pretty cool mountains in that telescope image.

    Now for the serious thing. Where do the scientists come up with ideas like that? Granted, i do have a few years of Chemical Engineering under my belt, but how could it be snowing? One would think that after all this time, that the system (weather) on Titan should be more or less at a steady state condition. It is too cold on Titan to allow for liquid water so the snow couldn't melt. It can't evaporate either since, according to scientists in the article, the atmosphere is 10 times thicker than here on earth. Snow isn't going to vaporize at 10atm. The last possibility is that strong winds could be picking snow up from the surface and lifting it to the atmosphere where it can rain down once more. This contrasts with another NASA article stating that the 'fog' on Titan is not turbulent, but dead still, this was stated to shut out theories that these 'bright' spots were merely weather phenomena like seen with Jupiter's Red Spot.

    Anyone want to enlighten me or comment on this further, this article has me quite intrigued.
  • Even if they don't fix the doppler problem, the Cassini 'mothership' has a radar system on board, which they will use to 'scan' Titan every time they pass, (probably about a dozen times during the mission), and from the radar echos, they will be able to map out a fair percentage of the moon's surface. The Huygens probe will give a 'close up' of the properties of the atmosphere, and if they're lucky, a small section of the surface.
  • Although people have already probably said much of what i'm going to say, here it goes... Snow doesn't have to be water ice. Many other chemical compoinds can freeze in different conditions and it may be that the "snow on Titan is one of these. Also, the weather is not in steady state mostly due to the tidal forces of Jupiter. The prime example would be Io. Sorry guys if these have already been mentioned.

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