Oceans Potentially More Common In Solar System 182
nairolF writes "The AIP Physics News Update has a brief note on how water oceans might be more common in the solar system than previously thought, rendering useless the old notion of a narrow "habitable zone" in solar systems, outside of which life cannot exist."
But what good is a beach... (Score:3, Funny)
Another related article... (Score:3, Informative)
Shameless journal plug? Not really, just an article the was rejected...
Re:Another related article... (Score:4, Funny)
All these worlds are belong to us. (Score:2)
Re:Another related article... (Score:2)
-l
Let's roll (Score:2)
If it's that much more likely to find a place to live, then I'll just be wishing that much more for a mission to go out and find them. Put enough people on a big enough ship and eventually maybe they'll get there. Maybe not in their lifetime, but I'm sure they'll be able to figure out what to do.
Re:Let's roll (Score:2)
Not if they're a bunch of hairdressers, PHBs and advertising execs...
Water on a rock? (Score:2)
And I always thought Pluto was just a big frozen asteroid. Does it have enough mass to keep water? This seems like a typo to me. (Unless frozen water now counts as an ocean.)
Re:Water on a rock? (Score:1)
Re:Water on a rock? (Score:1)
Re:Water on a rock? (Score:3, Interesting)
Remember that Charon, Pluto's moon/co Planet is close to half of Pluto's mass. The tidal force they exert on each other is significant... probably enough to keep water liquid (warm enough to support life? I dunno 'bout that) near Pluto's center.
This is, of course, assuming that Pluto is mostly made of cometary ice, rather than rock, which a lot of cosmologists think is the case.
Astrophysicists please correct me on the details.
Dead Scream...
Re:Water on a rock? (Score:1)
Re:Water on a rock? (Score:1)
Jeez. If oceans are so plentiful... (Score:5, Funny)
tcd004
Janet Reno Margolis for Florida Gov. [lostbrain.com]
Re:Jeez. If oceans are so plentiful... (Score:1, Offtopic)
POSITIONS WANTED: DO YOU SMOKE CRACK DAILY? DO YOU MAKE BIASED, UNEDUCATED CHOICES? IF SO, WE WANT YOU TO MODERATE FOR US! JUST CONTACT SLASHDOT.ORG.
Re:Jeez. If oceans are so plentiful... (Score:1)
To quote (Score:5, Funny)
Re:To quote (Score:1)
Re:To quote (Score:1)
or sometimes even coffee! [etenet.com]
"Ooooh!"
"What's the matter, too hot?"
"No, too sweet!"
Re:To quote (Score:1)
Re:To quote (Score:2)
Dr. Stevenson previous paper (Score:5, Informative)
Re:Dr. Stevenson previous paper (Score:2)
Here's an interesting paper on the same subject...
...and if you still believe in habitable zones, like most of the astronomical community, there are some interesting papers talking about habitable zones in the systems with known extra-solar planets. For instance...
- Can terrestrial planets exist in the habitable zones of known exoplanetary systems? [u-strasbg.fr]
- The stability of the orbits of terrestrial planets in the habitable zones of known exoplanetary systems [u-strasbg.fr]
Al.This makes inhabiting other planets easier (Score:4, Interesting)
This may make the Jovian and Saturnian satellites the prime real estate (aside from Earth) in the Solar System (whoa, echoes of Larry Nivem) Who needs the dry, dusty Moon or Mars.
Of course, all bets are off if life is discovered on Titan or Ganymede. Greenpeace would probably start a petition to leave the environment alone, so the single celled organisms can prosper while humanity suffers on an increasingly overpopulated Earth. Then again, if it's the Chinese that get their first, well, we know how what they did to the Three Rivers Gorge, goodbye extraterrestial life, hello New Gangzhou!
Re:This makes inhabiting other planets easier (Score:1)
Re:This makes inhabiting other planets easier (Score:1, Troll)
Then again, if it's the Chinese that get their first, well, we know how what they did to the Three Rivers Gorge, goodbye extraterrestial life, hello New Gangzhou!
This possiblity terrifies me. Look at the population growth of the Chinese! We Americans claim to be a "superior" nation yet we can't even touch the population numbers the Chinese are putting out. How can we hope to compete in fields such as primary experimental medicine and foreign occupation without any excess population? The Chinese have neary 3 billion people to rival our puny half a billion. If this story is right, and we're ready to move into space, it's pretty obvious what the outcome will be: the Chinese will leap ahead of us due to their superior population growth and colonize the Galaxy first.
My question is: what's their secret?
Re:This makes inhabiting other planets easier (Score:1)
The Chinese have neary 3 billion people to rival our puny half a billion. If this story is right, and we're ready to move into space, it's pretty obvious what the outcome will be: the Chinese will leap ahead of us due to their superior population growth and colonize the Galaxy first.
Please god, tell me this is a troll! There are 1 billion+ people in China, 1 billion in India, and a little more than a quarter billion in the US.
Re:This makes inhabiting other planets easier (Score:1)
Re:This makes inhabiting other planets easier (Score:1)
As we have seen numerous times in the past these leaps into the unknown or untamed will not only broaden our horizons but create new types of occupation, habitat, and science. Without these pushes onward we would grow to be static, fearful, and conservitive nothing that will withstand the need for sociological and ontological progress; so what, we can forever enshrine the even now ineffecient paradigms of the 20th century? I think not.
Re:This makes inhabiting other planets easier (Score:3, Insightful)
The fact that space colonizatoin cannot relieve population pressures does not imply that space colonization is not a good idea for other reasons. There are resources to be harvested, knowledge to be gained, and (as you point out) having humans on more than one rock increases the species chance of survival.
But it's still the case that the planet's population is increaseing by several people each second; just to keep up with the growth, every three days you'd have to build a new space-city the size of San Francisco and transport enough people to fill it [overpopulation.org].
Re:This makes inhabiting other planets easier (Score:2)
Are you aware that a recent study published in Nature predicts that population growth will level off over the next 100 years?
Lots of good links here.
http://www.nature.com/nature/fow/010802.html [nature.com]
-l
Oh, man... (Score:4, Interesting)
Just because the life forms we know about need water to live doesn't mean that any life that may or may not be in the rest of the universe needs water.
I mean, really, can we assume that all life in the universe is carbon-based and needs water to live? I don't think so. It's entirely likely that if we were to discover life, we wouldn't actually recognize it as such.
Just my random thoughts.
Re:Oh, man... (Score:2, Interesting)
This has been my complaint with the narrow-thinking SETI crowd for a long time. Just because we need water here on this planet for life (or think it is necessary), does not ipso facto require water to be necessary on other planets for life.
Even the concept that the only other possibility is silicon-based life forms seems quite limiting.
Re:Oh, man... (Score:5, Insightful)
Re:Oh, man... (Score:2, Interesting)
Re:Oh, man... (Score:1)
Re:Oh, man... (Score:3, Insightful)
1: H2O is quite light. It's only 18g/mol. There's no other combination _I_ can think of that would be as light, as we humans are made up of a lot of water.
2: H2O is slightly polar, so it 'sticks' to certain structures a little more. Oil would be an interesting substitute to water, but oil is large polimer chains. Too hard to create. However Ions would disrupt other chemicals. Also, Ions require water to have charge.
3: Most of all biological elements are within the top 10 elements on the peridic chart. The reason these are used is because nuclear fusion within the sun allows these to be made with much greater abundance. This reason also coves why no Earthen creatures use silicon instead of carbon.
4: If you can accept the above examples of why water is better than other mostly inert transfer chemicals, then tempature also comes into play. I know of no animals that use solid or gaseous blood. All use liquid of some type, just because diffusion (or in water, osmosis) is easier to transport chemicals. The tempature of water being a liquid is between 255K and 310K , so most planets are eliminated just because of the tempature needs strict control.
A simple question about life in general: What grows faster, plants in the rainfores or plants on Antartica?
Re:Oh, man... (Score:3, Interesting)
that need not be the case for things elsewhere
in the universe.
2. Water has many unique properties but none
of these may be needed by lifeform X.
3. Supernovae create abundant iron. Are we to
presume that lifeforms near supernovae are
iron based?
4. Blood? Why does lifeform X need blood? Are we
now presuming anatomy?
To take a slightly pessimistic view, in a few
hundred years humans may have driven themselves
to extinction leaving behind smart silicon-based
computers. Now you've got a race that needs no
blood and uses primarily copper and silicon to
replicate. Water may still be important for
some industial purposes but not in as large
quantities.
Re:Oh, man... (Score:1)
The tempature of water being a liquid is between 255K and 310K
I'm confused. Last I heard, water's melting and boiling points are 273 and 373 K respectively. Did or I miss something, or did I get my biology degree on luck?
And last I can remember, when I was walking around outside at 255 K, the water I saw was all quite solid.
Re:Oh, man... (Score:1)
Josh Crawley
Re:Ammonia? (Score:2)
Re:Ammonia? (Score:1)
Josh Crawley
Re:Oh, man... (Score:1)
Actually, thats wrong, Earth itself has MUCH more silicon than carbon, ever go to the beach? or the desert? You are right in a logical aspect, but on earth your premise is wrong (that silicon would be less abundant). One of the main reasons we don't use silicon is the strength. In biology class you learned that we have lots of long, long carbon chains in our body, which do lots of things. Silicon has a larger outer shell, causing the electrons to have a weaker bond to the atom, thus covalent bonding would be weaker. so, if we had long silicon strands, they would have a higher chance of breaking.
Re:Oh, man... (long answers) (Score:2)
up of a lot of water.
Water is light, but it is dense (1.) Most organic solvents are density roughly 2/3rds, although they are more compressable than water (so they'd be roughly density 1 under high enough pressure.) Water's gross physical properties (density, viscocity and so forth) are important for a multicellular organism but, actually, if you were just a single alien cell, might not matter.
2: H2O is slightly polar, so it 'sticks' to certain structures a little more. Oil would be an interesting substitute to water, but oil is
large polimer chains. Too hard to create. However Ions would disrupt other chemicals. Also, Ions require water to have charge.
Ions require something polar (alcohol would do) to pair with, or they won't disaccoiate with their counterion. It need not be water - it could be alcohol, or it could be something exotic like liquid SH2. Atoms heavier than sulfur or iodine are insuffiently electronegative to hold much of a negative charge in a polar bond, so probably wouldn't be suitable.
The real problem is that your non-water based cell needs some way to seperate itself from the environment. If you're willing to call any self-replicating molecule "life," this may not be a requirement, but if you're looking for anything that's at least a recognisable organism, even if microscopic, this is a hard requirement to fill without water (or HI or H2S.)
The way cell membranes work is they have an oily portion (the membrane) with ionic stuff on the inside and the outside. So, you have a little bubble of water (the cell) wrapped in the oily membrane which is much like a soap bubble.
Now, in an oily solvent, at the right temperature, you might be able to have the reverse - like a hollow bubble of water floating in liquid soap. However, the forces that push small amounts of something polar out of a non-polar solute are MUCH WEAKER than the forces that push something oily out of water. This results not from an energetic effect, but from an entropic effect:
Water in a solvent state is fairly disordered, capable of forming H-bonds with different waters on all sides of it, and of tumbling around and forming different H-bonds. If you introduce a big oil molecule into the water, there are a number of positions that the water can't tumble into (people describe this as a crystal-like cage but that is inaccurate) so the water molecule becomes more ordered. This increase in order is extremely unfavorable, so all of the oily molecules are pushed out of contact with the water and into oil droplets; like when you mix oil and vinegar together.
The above is called the "hydrophobic effect" and it is the basis of how cells form embranes AND of how proteins become structured. It is pretty much the basis of all life. A similar effect does NOT occur with oily solvents! In fact, it doesn't much occur with ethanol; as far as I know, only other molecules which are much like water show this property.
3: Most of all biological elements are within the top 10 elements on the peridic chart. The reason these are used is because nuclear
fusion within the sun allows these to be made with much greater abundance. This reason also coves why no Earthen creatures use
silicon instead of carbon.
Sorry, that's not true. The earth has more iron atoms on it than carbon atoms, and scads every element through 44 (Nickel) [sdsc.edu]. What you say IS true for the outer planets, which didn't have their light elements significantly blasted off by some kind of solar event. Alien planets, which got their heavy elements from different supernovae (that's where heavy elements come from) might have mercury and gold in abundance as well. We don't know.
4: If you can accept the above examples of why water is better than other mostly inert transfer chemicals, then tempature also
comes into play. I know of no animals that use solid or gaseous blood. All use liquid of some type, just because diffusion (or in
water, osmosis) is easier to transport chemicals. The tempature of water being a liquid is between 255K and 310K , so most planets
are eliminated just because of the tempature needs strict control.
I cannot see life arising in solid state, because if the molecules can't move, you can't do the kind of complex molecular recognition chemistry that we understand as life.
In a gaseous state, same problem for reverse reasons - the molecules can't find each other.
That said, you can have pockets of liquid water (underground, say, or under higher pressure) at much higher temperatures. Other molecules with many of the properties of water (possibly enough) could be liquid at much lower temperatures. There is an outside chance that much larger molecules might be suitable and liquid at higher temperatures.
Really exotic solvents - like molten table salt - require temperatures so high that processes dependent on a high degree of order (like life) could never arise.
Another big problem is that complex organic solvents (polybenzenes and such) do not arise spontaneously, while water and amino acids do.
Long story short - a few very water like solvents, like HCl, H2S or HI - might substitute for water and might extend the range of allowable temperatures somewhat. However, nonpolar solvents for life, and silicon based life, appear impossible.
The one thing that is important to remember in determining viability zones is that all of the planets and some of the moons give off their own nuclear heat from fission; especially the earth and other seismically active bodies like Io. This nuclear heat might substitute for solar heat for bodies well outside of the range of their primary's warmth; especially if these alien planets were formed in much closer proximity to a supernova.
Re:Oh, man... (Score:5, Insightful)
The statements is not incorrect. The implication you take from it is incorrect. "If A then B" does not logically imply "If not-A then not-B".
(Though it is a fairly common mistake, so it could be argued that science writers might want to take it into account when they write their articles.)
Re:Oh, man... (Score:1)
We can correctly say, "If there is water, then there can be life." If A, then B.
The mistake is saying, "If !A, then !B", "If there is no water then there cannot be life." I agree that this is wrong.
But logically "If !B, then !A" is true I believe. Thus we get, "If there cannot be life, then there is no water." That seems to be the reasonable conclusion, but still doesn't sound right.
Ah, now I have it. The inability of life means there cannot be water, otherwise there would be a chance for life. Got it.
Now, does that mean anything? Not really. Oh, well.
Re:Oh, man... (Score:1)
A | B | A->B
0 | 0 | 1
0 | 1 | 1
1 | 0 | 0
1 | 1 | 1
The only time A implies B is false is if we have B without having A.
Re:Oh, man... (Score:1)
Re:Oh, man... (Score:2)
However, this is a moot point, as we're working with false premises here to begin with. Water does not necessarily imply life at all. Drill several thousand feet into a glacier and see what's living there. Or, seal a canister of pure water and shoot it into space. In either case, you can find water without life.
Arguing with false premises isn't even arguing at all.
Re:Oh, man... (Score:2)
I'm sorry, but you are factually incorrect. Please refer to almost any textbook on Boolean logic, or a medium-to-advanced Web text on same (i.e., not simplified for search engines only). "If A then B" means only that "A and not(B)" is not true; "A and B", "not(A) and B", and "not(A) and not(B)" can all be true if "if A then B" is true.
The term you are probably thinking of is "if and only if", commonly abbreviated to "iff". "If and only if A then B" means that either "A and B" or "not(A) and not(B)" must be true. This is the common English meaning of "if", however it is not the logical/academic usage which computers, and programmers (most of the time), use - thus, it is not the common usage within Slashdot's audience.
Which does not, of course, change the fact that you are right about being able to find water without life. However, water is a good indicator for life: there is a much higher probability of finding (Earth-like) life where there is water than where there is none. It is not proof, of course - what might constitute "proof" is in question, though I suspect it might suffice to launch a probe with a microscope to the location in question and observe some single celled organisms moving around.
Re:Oh, man... (Score:2)
A->B is logically equivalent to !B->!A.
Work it out in a truth table, if need be:
A B A->B
t t t
t f f
f t t
f f t
If B is false, the only time the statement works out to true is if A is also false.
From your definition (straight from the truth table):
If A then B" means only that "A and not(B)" is not true; "A and B", "not(A) and B", and "not(A) and not(B)" can all be true if "if A then B" is true.
Notice that if B is false, the only time the statement itself is true is if A is also false.
Then again, I only got a B in the course overall, so maybe I didn't understand the point of this at all
Re:Oh, man... (Score:2)
Nevermind. ^_^;;;
Take a look around (Score:2)
Your point is perfectly valid, but I think, for the purposes of narrowing the search, we must start with what we know - what we observe around us right now.
I used to hold the belief that life could possibly form in all manner of environments...
Until it occurred to me that, right here in our own solar system, there are all manner of environments right under our noses. And so far as we can see (which is not that much, admittedly), there is no life on any other planet than Earth.
In fact, even within the narrow range of environments on Earth, we can observe a gigantic difference in the quantity and diversity of life between, say, a tropical rainforest and an arctic desert.
Much as I would like to believe that life can spring up in all kinds of envrionments, the evidence we've seen so far doesn't seem to support it. In my (very uneducated) opinion, it really does look like the warm and wet climate is best for life.
Re:Oh, man... (Score:2)
Re:Oh, man... (Score:1)
Of course not. Take Cybertron for example. Life evolved from naturally occuring gears, wheels, and pulleys.
It's entirely likely that if we were to discover life, we wouldn't actually recognize it as such
Exactly. They just look like small plastic toys to us. But remember, they're "more than meets the eye".
The Black Cloud (Score:1)
Ever read Fred Hoyle's "The Black Cloud" [amazon.com]? Besides being the best science fiction I've ever read, it contains a highly interesting life-form, which, despite it's MASSIVE intelligence, had never thought of the possibility that there might life on planets...
Re:Oh, man... (Score:1)
http://tabla.geo.ucalgary.ca/~macrae/Burgess_Sh
To see that Life on Earth has not always fit into the forms we easily recognise as "Life"
Water, albeit essential to life on THIS planet may NOT be esential for "life" elsewhere.
Even discounting the variety of fossilised life in the Burgess Shale one need only look at the diversity of "life" on Earth to recognise that "Life" comes in many forms.
Just my $0.000000002 worth
Keith
Re:Oh, man... (Score:2)
Here is the reason: biochemical reactions are based upon the movement of protons and electrons around. Actually, all of biochemistry is basically moving stuff around. Move a pair of electrons, form a bond, break another bond, loose a proton.
Thus, a lot of chemistry requires acids/bases to work. Since your acids and bases are basically H+ and OH- ions (along with the odd carbocation/anion, etc.) you will almost always produce water somewhere along the line.
There just aren't a lot of places to stick excess protons and electrons. After oxidation and reduction reactions, you're eventually left with some byproduct that you don't really need.
One of those happens to be water. Carbon dioxide is another one of those molecules that would almost have to show up somewhere.
The world may be a big, odd place, but the general fundamentals of biochemistry don't change. If life exists elsewhere, it is almost certain to require water at some point in its life.
Full Text of Article (It's REALLY short...) (Score:2, Redundant)
Oceans Might Be Common and Diverse
Oceans might be common and diverse in our solar system and in other solar systems, according to David Stevenson of Caltech, who regards the old notion of a narrow "habitable zone" (Venus too hot, Mars too cold, Earth just right) for liquid water oceans as erroneous.
Stevenson spoke earlier this week in San Francisco at a meeting of the American Geophysical Union at a session intended to bring together two scientific communities that scrutinize very different realms--the planets and the seafloor on Earth.
The connection? Observations from the bottom of the ocean show that microbes thrive both in near-freezing seawater and in near-boiling effusions from thermal vents. These conditions might turn up in many other planetary environments.
For example, the Galileo spacecraft has provided evidence for watery oceans on three of Jupiter's moons-Callisto, Ganymede, and Europa. Subsurface oceans could be kept liquid by warmth from tidal forces (Jove wringing its satellites) or from radioactivity. Torrance Johnson of JPL, also speaking that the meeting, said that Europa's ocean might be 75-150 km thick and could thus harbor twice the water in Earth's oceans.
Stevenson added that observations also hint at oceans on Titan, Triton, and Pluto. In the case of Titan (soon to get the Galileo treatment when the Cassini spacecraft reaches Saturn in 2004) an ocean would be a mixture of water and ammonia (acting as antifreeze). Under some circumstances water might even be found inside Uranus and Neptune.
Other forms of life? (Score:4, Informative)
It strikes me as rather narcissistic to believe that the definition of life is somehow rooted to the way things worked out on this planet...
Can anyone think of any other substances that behave as dynamically as water in different temperature ranges?
Non-H20 life. (Score:1)
Of course if you meant non H2O life, that is an entirely different story. My own expert opinion is that we would not recognize any such life form unless it was intelligent. And even then we would be likely to think of it as some form of machine rather than something actually living.(Paranoid crackpots like Stephen Hawking do speak of machine life - but only as an extension of our own creations)
Re:Non-H20 life. (Score:3, Insightful)
Hell, if consciousness is just a byproduct of a complex system, we would never know it because there would be no way to relate to such a system. I wouldn't be surprised to learn that there is some kind of life sharing the same planet with us that we never noticed because it functions on a completely different level.
Re:Non-H20 life. (Score:3, Funny)
Greetings!
The "Others"
Re:Other forms of life? (Score:3, Informative)
Yeah, science fiction has postulated silicon-based life (the kind Kirk almost killed in ST:TOS), or chlorine breathers (like the Kloros in that Asimov story, C-Chute), but I haven't heard that anyone has postulated any plausible biochemical processes (akin to ATP) that could support such life. Anyone got any pointers?
doubtful (Score:2, Informative)
There really aren't a lot of other choices. It is unimaginable really to have life (at least any kind of life we could interact with) in solid or gaseous form, so you need a solvent. Methane, carbon dioxide, helium, and hydrogen are abundant but nowhere near as versatile as water. Liquid ammonia or some mix of solvents might work, but they don't look promising.
So, people have thought about this but not really come up with any plausible alternatives so far. Water and carbon seems to be the only reasonable cohice. But if someone can make a plausible argument, I think the scientific community is receptive.
Another.."Life based on what we know" article. (Score:4, Interesting)
"I can't argue that I'm not an idiot." - Jon Katz
Surfing? (Score:1)
New bottled water competition (Score:1)
Try new "nector of the gods" water, bottled straight from the oceans of Saturns's Moon Titan!
Really (Score:2, Funny)
Under some circumstances water might even be found inside Uranus...
Old news, the Kaopectate people have known that for yearsIn further news... (Score:5, Funny)
Oceans are believed essential for life, but so was the habitable zone. It is the height of "optimism" to believe that if one is wrong, the other must be even more right than before.
There is life on Earth which exists in deep, oceanic trenches, near hot volcanic vents. Since that life could not exist prior to the volcanic vent opening, it can be assumed that the formation of life, at it's most basic, is occuring on a regular basis. These life-forms may or may not have any nucleic structures we would recognise.
For this reason, until such extreme life-forms on Earth are better understood, and the range of conditions in which they can form are better quantified, only the very brave, or very stupid, could claim that "factor X will make life more/less abundant in our Universe". All we really know is that the picture is a hell of a lot more complicated than it used to be.
Re:In further news... (Score:3, Interesting)
Maybe I missunderstand you. Are you saying that those little white crabs and shrimp evolved completely separate from the crabs and shrimp that live in shallow water and look exactly like them?
Re:In further news... (Score:2)
Spores, seeds, and other things are known to travel great distances through environments they couldn't actively prosper in. Just because there is a large gap between thermal vents and other places life likes to live, doesn't require that life arrise independantly at the vent. It's nice to think that life might be rather easy to get started, but we don't really have the evidence or understanding to make that judgment.
Seriously.... (Score:3, Informative)
The article:
""Oceans might be common and diverse in our solar system and in other solar systems, according to David Stevenson of Caltech, who regards the old notion of a narrow "habitable zone" (Venus too hot, Mars too cold, Earth just right) for liquid water oceans as erroneous.
Stevenson spoke earlier this week in San Francisco at a meeting of the American Geophysical Union at a session intended to bring together two scientific communities that scrutinize very different realms--the planets and the seafloor on Earth.
The connection? Observations from the bottom of the ocean show that microbes thrive both in near-freezing seawater and in near-boiling effusions from thermal vents. These conditions might turn up in many other planetary environments.
For example, the Galileo spacecraft has provided evidence for watery oceans on three of Jupiter's moons-Callisto, Ganymede, and Europa. Subsurface oceans could be kept liquid by warmth from tidal forces (Jove wringing its satellites) or from radioactivity. Torrance Johnson of JPL, also speaking that the meeting, said that Europa's ocean might be 75-150 km thick and could thus harbor twice the water in Earth's oceans.
Stevenson added that observations also hint at oceans on Titan, Triton, and Pluto. In the case of Titan (soon to get the Galileo treatment when the Cassini spacecraft reaches Saturn in 2004) an ocean would be a mixture of water and ammonia (acting as antifreeze). Under some circumstances water might even be found inside Uranus and Neptune.""
Europa does have very likely evidence of a liquid ocean, but the article then uses that to 'assume' of living creatures there (bac). How can there be? Complex nucleotides and a slurry of other complex chemicals are required for 'life' to occur. Another problem is energy entering/leaving the system. The Earth is quite close to the sun, but europa can rely on nearly 0 energy from the sun (at least as useful radiation). Tidal energy is energy none the less, but it's too limited, even coming from Jupiter.
Energy, yes but useful, no.
Josh Crawley
Re:Seriously.... (Score:2, Interesting)
Europa does have very likely evidence of a liquid ocean, but the article then uses that to 'assume' of living creatures there (bac). How can there be?
While I would be the first to argue that we have no proof of life, the martian meteorites [nhm.ac.uk] not withstanding, Europa is probably our "best bet" to find it inside our own solar system.
For instance have a look at these papers from the AAS DPS meeting,
or even
- Europa's Habitability follows from Classical Dynamical Astronomy [u-strasbg.fr]
Al.Re:Seriously.... (Score:2)
This is the same tidal energy that causes Io to radiate excess heat in the form of volcanic eruptions. Certainly the effect is less near Europa, but according to this page [seds.org] your assertion is still up in the air.
Re:Seriously.... (Score:1)
Re:Seriously.... (Score:3, Informative)
Bacteria are tough; they can spore up and be very hard to kill. (That's why anthrax is such a bitch to deal with.) Earth bacteria survived for several years unprotected on the moon [nasa.gov].
Oceans, oceans everywhere... (Score:5, Informative)
Also, on Earth, there is a plethora of water below the surface, although you would not want to drink it. It's usually saturated in salts like calcium or sodium chloride, carbonates, and sulfates. However, even 10 km below the surface of the Earth, in hot conditions and high pressures, 0bacteria thrive in these conditions (as they do in the Hydrocarbon deposits as well).
Given that Mars has plenty of surface evidence of (geologically) recent free flowing water, the scientific community would be remiss to assume that subsurface water does not exist. It likely has a lot of brine belows it's surface, perhaps rich in Iron salts.
Also, there are moons of Jupiter, like Europa (which is basically 10 km of ocean from what we can see on the surface) and Ganymede (with a lot of hydrocarbons) where conditions that bacteria and simple one celled life require exist. Given that we have already learned that bacteria in hostile environments on Earth (Antarctica, for example, in very dry and cold conditions) can hibernate for millions of years, it's conceivable that rocks knocked loose from Earth from the occasional large meteor (i.e. asteroid or comet) could transport bacteria to Mars and elsewhere. I think that if life did not evole there, it was transported from Earth by this process (or perhaps even the other way). Some people have speculated that bacterial or similar life found on Mars or elsewhere within this solar system is completely different from that found on Earth -- I would postulate that it is probably no more 'alien' that what we might find in the ocean near black smokers, that big underice lake in Antarctica (can't remember the name), or a barren, cold, high altitude mountain.
---this is not your kill9 sig
Re:Oceans, oceans everywhere... (Score:2)
I would guess that low order protists like bacteria, slime molds, etc. on other planets would be similar to those on earth. Any higher-evolved life forms would be quite a bit different. Bacteria in isolated environments (deep ocean, polar lakes) are basically the same as any other bacteria on earth, single-cell with a nucleus and a penchant to multiply. But look at some of the fish and crustaceans that they find near the atlantic vents - freakish things by everyday earth standards.
If there were surface life on Mars (personally I don't believe there is) it would also have to be evolved to the Martian environment. Maybe the heart-lung system isn't the most efficient circulatory system for Mars. Maybe the high amount of CO2 in the atmosphere makes a better case for photosynthesis. We won't know unless we go there.
Re:Oceans, oceans everywhere... (Score:2)
You're mostly right, but water is a solvent, it can't be saturated.
Sure it can. [iversonsoftware.com]
--MarkusQ
This article has nothing to do with oceans... (Score:3, Interesting)
... and how common they are. It has to do with the common belief that for an ocean to be hospitable, it needs to be within a certain threshold. They've basically taken evidence that microbes thrive in near boiling water and near frozen water, and apply that to the other suspected oceanic environments in the solar system. This says nothing about the environment required to form life however. Overall, nothing new here....
Re:This article has nothing to do with oceans... (Score:1)
I would hate to be a scientest when they realize that all the science we discover on Earth could be tossed out the window when they find another habited planet. But thats just my opinion.
Interesting News (Score:1, Interesting)
Think outside the globe people...
Scientific Absolutes (Score:2, Insightful)
Scientists (and probably the media covering them) have had a habit of making such absolute statements as these for centuries. Recall the common theories of the universe around the time of Gallileo and Copernicus?
Isn't it about time scientists and those who report their findings wake up to the fact that what we know today is only what we know today, and that things might be diferent tomorrow? Report the findings, sure, but make sure your language shows that we are still looking for more information, still finding new things every day...
Re:Scientific Absolutes (Score:1)
Isn't it about time scientists and those who report their findings wake up to the fact that what we know today is only what we know today, and that things might be diferent tomorrow?
Wow! Really? You mean that what we know might change tomorrow? When did you come up with this AMAZING insight into the workings of human knowledge? Let me share this with my scientist friends, because I am quite certain they have never considered this possibility!
Look, doofus, this point has been argued ad nauseum. The only people I have ever met who believe in absolute and eternal truths are the religious types, not scientists. You wanna be a member of the language police, you just go right ahead. Just expect to lose a few acquaintances, cuz people like you generally annoy those around them.
- Rev.Argh (Score:5, Informative)
Ok, lets get some things straight. There's evidence that liquid water can exist in places outside our old 'habitable zone'. We know that organisms can thrive in boiling and subzeo (but still liquid) water, as well as surviving frozen inside ice (as happens annually in the ice shelves of antarctica).
So, this means that its *possible* for life as we know it to exist in these extraterrestrial oceans. No one is saying its there, just that its worth a look. Likewise, no one has proven that life can't exist without water. However, the only kind of life we *know* exists, does require water, and is carbon-based. I hope someday that we find that life exceeds this "narrow" category, but since we'd first just like to find any life at all, where do you think we're going to look? For the moment, time, energy, and resources are most likely to give results if we apply them according to our best information about life, however meager.
Rant over. Now get the hell off my lawn you kids!
Can you prove this? (Score:2, Insightful)
should read "...outside of which life as we know it cannot exist."
It really bothers me when people leave that part out. Though we haven't found any evidence yet, living organisms in other solar systems may very well have adapted to a completely different kind of environment than we have here on Earth. Just because we don't know about it or understand it yet doesn't necessarily mean it doesn't exist.
--SONET
BTW (Score:2, Insightful)
had they read Sitchin... (Score:1, Interesting)
Not quite useless, I don't think (Score:3, Interesting)
rendering useless the old notion of a narrow "habitable zone" in solar systems, outside of which life cannot exist.
From my limited information on this subject, I've understood that the habitable zone is used in the context of planet forming and that the reason behind certain planets having certain compositions is their position in the solar system, mainly distance from the sun, while they were forming. Therefore the habitable zone is the area where if a planet forms there it will likely have the characteristics of a planet capable of sustaining life as we know it. The article suggests that the habitable zone only refers to an area that can sustain life now that all the planets are here, which is really only descriptive of human life and not other, unknown organisms (or possibly known like the microorganisms discussed in the article.)
Liquid water needed, plus (Score:5, Insightful)
Re:Liquid water needed, plus (Score:2)
This environment also would have been safer from solar radiation (remember, life may have been necessary to create the ozone layer), and could have provided its energy source even earlier than the sun, since volcanic ash may well have been blocking the sun continuously during the active volcanism on the early Earth -- volcanism that also would have made the thermal vents quite common.
In general, the isolation of the extremophiles from the rest of the biosphere, and their independence from so many potentially life-generated conditions: an ozone layer, an oxygen-rich atmosphere, a carbon-regulated climate allowing liquid water on the surface, says to me that they may be prime examples of life that would arise first on a planet.
I consider it entirely possible, if not likely, that the hydrothermal vents hosted Earth's first life, and thus could host the genesis of life elsewhere.
Life on Venus? (Score:2, Insightful)
But this would of gradulary developed, Venus started in similar condtion to Earth, therefore any life that managed to get a toe-hold on Venus would have had time to adapt their bio-chemistry in a similar way to those of the Earth's sub-sea vent creatures (~150C, high sulphuric acid concentrations).
I have heard that 'Oxygen destroys naked DNA'. Therefore there can be no DNA-based life on Sol 3, but when we look at Sol 3, we are hard-pushed to find somewhere where there isn't life of some sort.
A puzzle that fits our pieces? (Score:2)
Complex organisms are a product of their environment, literally. You know... evolution? By seeking for life only on planets with conditions similar to ours, are we not merely trying to find a puzzle that fits our pieces? We need water, we need certain temperatures, etc, because we evolved to fit into that environment. Life on another planet would evolve to fit conditions on that planet, it would not try to evolve to fit conditions suitable for earth organisms. :)
I believe that if we find life beyond earth, it will very likely exist in a different environment and function on different chemical principles using different biological mechanisms than we have ever encountered.
Now if you're looking for a planet to move to... that's different.
Somewhat offtopic - habitable zone (Score:2)
Of course there's liquid, of course there's water (Score:2, Interesting)
pedants corners. (Score:2, Informative)
Re:Great! (Score:2)
Re:Venus has an ocean (Score:2)
Re:Galactic habitable zones a misnomer... (Score:2)