×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

EPOXI Team Develops New Method To Find Alien Ocean

samzenpus posted more than 4 years ago | from the in-space-nobody-can-hear-you-swim dept.

Space 42

Matt_dk writes "Astronomers have found more than 300 alien (extrasolar) worlds so far. Most of these are gas giants like Jupiter, and are either too hot (too close to their star) or too cold (too far away) to support life as we know it. Sometime in the near future, however, astronomers will probably find one that's just right — a planet with a solid surface that's the right distance for a temperature that allows liquid water — an essential ingredient in the recipe for life. Now scientists looking back at Earth with the Deep Impact/EPOXI mission have developed a method to indicate whether Earth-like extrasolar worlds have oceans."

cancel ×
This is a preview of your comment

No Comment Title Entered

Anonymous Coward 1 minute ago

No Comment Entered

42 comments

water esential for life? (2, Interesting)

voogzy (1418593) | more than 4 years ago | (#28117453)

why should water be essential for life? and how do you define life anyway?

Re:water esential for life? (4, Funny)

commodoresloat (172735) | more than 4 years ago | (#28117475)

why should water be essential for life?

Because nothing truly brings out the flavor of a fine Scotch like a drop of water.

Re:water esential for life? (1)

John Hasler (414242) | more than 4 years ago | (#28117575)

Water is essential for our kind of life, which the only kind we know how to recognize.

Re:water esential for life? (1)

Anonymous Coward | more than 4 years ago | (#28118401)

Speak for yourself. I have been rooting out and R2-45 processing thetans for damn near two decades now.

Re:water esential for life? (1)

pinkj (521155) | more than 4 years ago | (#28117607)

while it's possible that water isn't essential, it's a good start to finding something close to what we would deam a living thing. if i'm looking for potatoes, i wouldn't be looking up in the trees.

Re:water esential for life? (4, Interesting)

jschen (1249578) | more than 4 years ago | (#28118093)

and how do you define life anyway?

Good question. There's lots of ways, but my personal preference in this context is a system that expends energy in order to combat entropy. Once you stop combatting entropy, you head towards thermodynamic equilibrium, and are dead. This definition may be overly broad (by that definition, my computer's memory chips are alive), but I suspect that if we find something that meets these criteria, it will be associated with life.

Re:water esential for life? (1)

Eternauta3k (680157) | more than 4 years ago | (#28118427)

This definition may be overly broad (by that definition, my computer's memory chips are alive)

Even better, by that definition our planet is alive. I think Gaia has copyright on that concept

Re:water esential for life? (1)

DigiShaman (671371) | more than 4 years ago | (#28118595)

Good question. There's lots of ways, but my personal preference in this context is a system that expends energy in order to combat entropy.

Talk about being a monkey wrench in the inner workings of the Universe. Then again, perhaps life is a way for the Universe's omni-present collective subconscious to be aware of itself as so to provide introspection.

Too philosophical, I know. Sorry.

Re:water esential for life? (0)

Anonymous Coward | more than 4 years ago | (#28119071)

Nothing in the universe combats entropy. Your statement is complete nonsense.

Re:water esential for life? (1)

Urkki (668283) | more than 4 years ago | (#28127291)

Nothing in the universe combats entropy.

I do! Entropy will only win over my dead body!

Re:water esential for life? (1)

oldspewey (1303305) | more than 4 years ago | (#28118143)

Water is a damned fine solvent ... incredibly useful for doing all kinds of biochemistry, and plentiful throughout the galaxy.

Close giants... (4, Informative)

cupantae (1304123) | more than 4 years ago | (#28117565)

As far as I know, most of the techniques used for detecting exoplanets depend on the planet being ~Jupiter mass and pretty close because then

-you get gravitational "wobble"
-you're more likely to be in line for a transit
-mass is enough for gravitational lensing

Re:Close giants... (2, Informative)

pinkj (521155) | more than 4 years ago | (#28117669)

the Herschel Space Observatory [esa.int] is suppose to help with that very problem by being able to detect much colder parts of the universe. it even has the ability to observe structural detail by detecting water.

From TFA.... (0)

Anonymous Coward | more than 4 years ago | (#28117649)

"They launch a sunbed at the planet and if a towel appears there are german lifeforms nearrby"

Water's nice, but ... (1)

PPH (736903) | more than 4 years ago | (#28117677)

... why not look for oxygen? Oxygen is pretty reactive and, absent some process (life?) that regenerates it, it will combine with other molecules. Find oxygen and there's likely something going on to make it.

Re:Water's nice, but ... (0)

Anonymous Coward | more than 4 years ago | (#28117709)

Water == H2O hence, finding water finds at least a means of generating oxygen....

Re:Water's nice, but ... (2, Informative)

cupantae (1304123) | more than 4 years ago | (#28117795)

Well, yes, but finding gases in the atmosphere by spectroscopy is a lot easier. Luckily, they can look for two things. High-5's all round

Re:Water's nice, but ... (1)

PPH (736903) | more than 4 years ago | (#28117865)

Water == H2O hence, finding water finds at least a means of generating oxygen

But water is inert. Water could have been sitting around for millopns of years doing nothing. The presence of oxygen implies an ongoing process generating it. Possibly life.

As We Know It (1, Interesting)

bruciferofbrm (717584) | more than 4 years ago | (#28117777)

Water as we know it contains Oxygen. Buy one, get the other for no extra charge.

Life as we know it is the rub here. Are we looking for planets that will potentially have life forms that are some how similar to those we know of on our own world?

Or are we really looking for a place to colonize one day?

If it is the later, then looking for water is logical.

If it is not, then really, open your mind and realize that 'life as we know it' is a very short sighted perspective. Out there in the universe is a silicon based civilization looking for worlds bathed in methane simply because it is quite obvious to anyone intelligent that this is the only type of work the 'life as they know it' could possible have a chance of being created.

Oh, and I would suggest opening your mind to broader horizons because some of those oxygen breathing, water oriented life forms I know can be real bastards.

Re:As We Know It (2, Informative)

MrMista_B (891430) | more than 4 years ago | (#28118099)

What makes you think they haven't thought of that? You're stating the obvious.

The reason they focus on 'life as we know it', is that /know how/ to search for 'life as we know it'.

By very definition, 'life as we don't know it' is more difficult to search for. How to you try to find something you don't know the characteristics of?

'Broader horizons' is one thing, but in a case we're trying to find extrasolar life, let's not invent artificial difficulties - it's already damn hard as it is.

Re:As We Know It (3, Insightful)

interiot (50685) | more than 4 years ago | (#28118109)

What are the alternatives [wikipedia.org] ? Carbon-sulfur [wikipedia.org] might be a reasonable option. Silicon-oxygen is a little further out. There are only so many atoms available, and their prevalence is dictated by stars [wikipedia.org] , so that puts a limit on what variations could be possible, and, well, there aren't that many.

Re:As We Know It (4, Insightful)

jschen (1249578) | more than 4 years ago | (#28118259)

Even on earth, the study of lithotrophs ("rock eaters" that get energy by oxidizing inorganic materials) is a decades-old field. They are found in all sorts of settings, though not a significant part (by mass, not necessarily by importance) of the biosphere. Many lithotrophs even engage in carbon fixation from CO2 using the energy they derived from "rock eating", and thus can live completely independently of any need for photosynthesis (even by other organisms). As for lithotroph metabolisms, your imagination is the limit. Lithotrophs even have commercially viable applications. Anaerobic oxidation of ammonia by nitrite, a reaction performed by certain "anammox" bacteria, is useful for the treatment of fertilizer-contaminated waste water.

Re:As We Know It (1)

gstoddart (321705) | more than 4 years ago | (#28119307)

Are we looking for planets that will potentially have life forms that are some how similar to those we know of on our own world?

Well, because if you look for conditions like your own world, you know you have at least a fighting chance. If you start looking for lifeforms with chemistry vastly different from your own, you have no basis to look at.

So, absent any workable evidence of a completely different life-form to us, you stick what what we do know works. That would be purely speculative as you'd have no way to look for it other than making WAGs about things you know nothing about. At that point, it kinda stops being science.

How would you even start to search for something you can't conceive of? At least looking for things similar to our own conditions you can screen out most of the candidates to a smaller sample.

Cheers

Why... (-1)

XPeter (1429763) | more than 4 years ago | (#28117789)

...Do scientists only look for planets that have oxygen or water?

You know, not everything is human and breathes air and drinks water. Who knows, you could have some green friends that breath helium and drink mercury. They could even have there own set of elements. Not everything is as we know it to be.

Re:Why... (2, Insightful)

4D6963 (933028) | more than 4 years ago | (#28118001)

Yeah sure, or they could breathe lead and drink plutonium, I mean what do you know!

Or maybe possibly these guys have a better idea than you do about what seems even remotely plausible or even likely and they're taking their shot at it?

Re:Why... (1)

Cassius Corodes (1084513) | more than 4 years ago | (#28118435)

On the other hand this is an actual opinion from a 15 year old! We cant just dismiss it out of hand. After all experts have been wrong before and therefore anyone's opinion is as good as any other. :D

Gas giants (2, Interesting)

Dasher42 (514179) | more than 4 years ago | (#28117811)

Considering the likelihood of a gas giant to have many moons of significant size, why do we insist on a planet in the goldilocks zone? Here we are considering Europa and Callisto for possible subsurface oceans, and even life, and how would it be to have moons in that orbital slot?

Re:Gas giants (4, Informative)

panthroman (1415081) | more than 4 years ago | (#28118211)

You raise a common question: why not look for life as we do not know it? Why are we looking for something so darn Earth-like?

Yes, life could exist elsewhere. There are soooo many possibilities. I mean, we seem pretty distance-from-the-star-centric, but even on Earth some critters aren't solar-energy dependent! Did you know Jupiter radiates more heat than it gets from the sun?

But basically, here's why we're looking for Earth-like planets:
Big gas giants are 0 for 4 on having life (that we know of)
Objects that do not revolve around a star: 0 for many
Small rocky planets: 1 for 4
Rocky Earth-sized planets that are 0.9-1.1 AU from a medium-sized star: 1 for 1

We have limited resources, so we are forced to narrow our scope. Narrowing our sights based on the few dozen studied objects in our solar system... it's easy to mock, but what else can we do? We can (1) keep searching through our own solar system to ameliorate some of the "sampling bias," and (2) look for rocky Earth-sized planets that are 0.9-1.1 AU from a medium-sized star. And that's pretty much what we're doing.

Re:Gas giants (1)

drinkypoo (153816) | more than 4 years ago | (#28121051)

You raise a common question: why not look for life as we do not know it? Why are we looking for something so darn Earth-like?

We can only look for things we know to look for. So far that's water, and radio signals. We're already searching for the latter.

Redneck planets (2, Funny)

PPH (736903) | more than 4 years ago | (#28117939)

If we're looking for planets that reflect a lot of blue light, we may end up finding ones covered with blue tarps.

Detecting colour patches (2, Interesting)

4D6963 (933028) | more than 4 years ago | (#28117985)

So if I got this right from TFA, they can tell there are oceans by how the amount of blue light changes? Doesn't it assume that the planet in question has large continents? I mean if the planet was pure ocean on the surface, then it'd always be a uniform display of blue. So basically what they do is detect different patches of colour, and if they find blue patches in the mix they'll assume they're oceans, am I right?

Also, using this technique of variation of light, couldn't they build a very crude longitudinal colour map of the planet? I mean, it would probably look like taking a map of Earth, squishing it to a height of 1 pixel in Photoshop and stretching it back, but they could get something like that, right?

Life in supercritical water? (3, Insightful)

jschen (1249578) | more than 4 years ago | (#28118177)

I just wondered something. Generally, the presence of condensed phase liquid water is considered a marker that tells us "Look for life here." Unfortunately, given our current technology, most planets we find are gas giants that orbit too close to the star to be in the "habitable zone". But gas giants, by virtue of being huge, have hugely high atmospheric pressures in the lower atmosphere. Couldn't supercritical water (i.e. water at a sufficiently high temperature/pressure that there is no distinction between gas and liquid) support life? Or, for that matter, supercritical methane, or any other supercritical medium? After all, we can run useful chemistry in supercritical fluids such as supercritical CO2. And if it can support life, wouldn't the possibility of life in supercritical water significantly extend the habitable zone?

H2O? (1)

Merc248 (1026032) | more than 4 years ago | (#28119013)

I'll be extremely happy when they finally find a planet with water, and not that crazy alien XYZ that I keep hearing about...

What the ***l is a red-green-blue filter (1)

RNLockwood (224353) | more than 4 years ago | (#28119023)

"he first version uses a red-green-blue filter; the second, an infrared-green-blue. "

What kind of filters are these? if It's a band pass the first just blocks infrared (assuming they use a silicon detector), or are they band pass filters used on sequential images, or are they band blocking taken on sequential images so that you get red + green + ir, and blue + green + ir, and red + blue + ir ? I'm assuming they they have just the one detector.

Pictures or it didn't happen (1)

alexo (9335) | more than 4 years ago | (#28139153)

I know that it's off topic but can anyone suggest when can one find (simulated) images of what an extra-terrestrial landscape could look like (with oceans or otherwise) that don't look too artificial? Preferably desktop wallpaper sized.

Google Images found several but the picking is slim.

Check for New Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Sign up for Slashdot Newsletters
Create a Slashdot Account

Loading...