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Scientists Find Water on Extra-solar Planet
Posted by
samzenpus
on Wed Jul 11, 2007 08:54 PM
from the there-is-no-tea-like-space-tea dept.
from the there-is-no-tea-like-space-tea dept.
amigoro writes "Scientists have, for the first time, conclusively discovered the presence of water vapour in the atmosphere of a planet beyond our Solar System, according to an article appearing in Nature. They made the discovery by analysing the transit of the gas giant HD 189733b across its star, in the Infrared using data from NASA's Spitzer Space Telescope. HD 189733b is a 'hot jupiter', a gas giant that is roughly the size and mass of Jupiter but orbits very close to the star, so no chance of life there."
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Hrrmph! (Score:5, Funny)
Re:Hrrmph! (Score:4, Insightful)
Parent
Re:Hrrmph! (Score:5, Informative)
Hydrogen is fairly common in the universe (90% of its composition), but oxygen isn't except in and near stars (because it is only created by fusion inside the stars and ejected free by supernovas). It makes sense that gas giants will pick up traces of oxygen and then form some water and it makes sense that rocky planets will have the potential to form water since the major constituent of silicious minerals is obviously quartz or SiO2. Any rocky planet that has had some differentiation process would likely have the silicious minerals float to the top like with the Earth and thus have a great potential of having liquid water form if the atmosphere could support it. Mercury, Venus, and Mars are great examples of places where the atmosphere could not support liquid water. On one side if do not have a powerful enough geomagnetic field, the solar wind will strip the atmosphere leaving the surface bare like Mercury and Mars. On the other side, if you gas the atmosphere too much with CO2 from volcanoes, the atmosphere will superheat allowing the water vapour to rise and be broken up by UV light like on Venus. So there is a sweet spot where the Earth exists to have a rocky planet with a strong enough geomagnetic field and enough gassing by volcanoes to support the atmosphere.
Parent
Re: (Score:3, Insightful)
It's the magnetic field (Score:5, Interesting)
On Venus too, it was the magnetic field -- or rather, lack thereof -- that did it. It's not just that some water gets split into hydrogen and oxygen, in which case it would just recombine sooner or later. It's that on Venus the lack of magnetic field allowed the solar winds to gradually wipe away the hydrogen. Venus is heavy enough to hold on th the slightly heavier elements, like Oxygen and Carbon anyway, even without a magnetic field. Hydrogen is a different story.
Outgassing CO2, well:
1. Earth spewed enough of that too, which is how it thawed back when cyanobacteria turned the atmosphere to O2 and the whole planet got deep frozen. (The Sun started a lot "cooler" and gradually warmed up. _Now_ it's warm enough to support life without a greenhouse effect, but in the beginning it wasn't.) I don't think there is any evidence that Venus spewed much more CO2 than Earth. On Earth just a lot of it got, well, buried right back. Say, in the Carboniferous era coal deposits.
The somewhat interesting corolary is that if we had too _little_ outgassing, then we'd have been really screwed. It took, IIRC, some 30% CO2 in the air to thaw that snowball Earth. Too little of it, and the deep freeze might just have continued long enough to be a total extinction event. Or at the very least a 1 billion year (or maybe more) pause in life evolution until the sun output went up some more.
2. Earth's original atmosphere was _methane_, which is a greenhouse gas about 200 times more potent than CO2. So if Venus would have been screwed by its outgassed CO2 atmosphere, the Earth should have been screwed 200 times harder (or close enough. Well over 100 times anyway.) In practice, that atmosphere on Earth just helped keep it warm enough at a time when the Sun was a lot weaker. If Venus had had a CO2 atmosphere at the time, well, it would have been a frozen snowball, quite the opposite of boiling off its water. In practice, it's a lot more likely that Venus started with a mostly Methane atmosphere too, only the hydrogen was swept away whenever some of it got broken up.
Pretty much if you start with water, methane and CO2, and continuously lose hydrogen, you end up with just the oxygen and carbon left, which means a lot of CO2. That's likely the short story of what happened on Venus.
3. There's an interesting extra factor there, which could have doomed Earth anyway, and that is: timing. If life or photosynthesis had started any later, for example, that methane and CO2 atmosphere would have sealed its fate. As I was saying methane is an _extremely_ potent greenhouse gas, so given enough extra time of gradually increasing solar output, it would have just boiled off the oceans. No liquid water, no life, game over.
Parent
CO2 from volcanoes? (Score:3, Funny)
Volcanoes? That's impossible! Al Gore told me that excess CO2 can only come from SUVs.
pebfab (Score:3, Insightful)
Yes and no (Score:3, Informative)
Well, yes and no. Volcanoes do spew all sorts of stuff into the air, the question is just how much of it.
Thawing up snowball earth I mentioned before took up to 30 million years, and that's with zero photosynthesis or other processes getting it out of the air again. So we're talking geologic timescales. Admittedly that required accumulating some 13% CO2 in the air (looks like I was remembering wrong when I said 30% before)
Re:Hrrmph! (Score:5, Funny)
Kind of like how theoretically, in spite of being a male who reads slashdot, I should be able to get laid. It's just pretty cool when I get conclusive proof of that theory.
Parent
hmm (Score:5, Funny)
The only extra solar planet I know of is Pluto, and we've already had that discussion.
no change of life like us (Score:5, Insightful)
Re: (Score:2, Funny)
I'm sure that Ludacris's response to that would be your too white and nerdy
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Re:no change of life like us (Score:5, Funny)
"And yet it may indeed be that ours is the easiest, and therefore most likely, form of life to get started."
o argument about it. Its a lot easier than, say, building a car. A car requires over 3,000 pieces - to make a human only requires 2 bumpers and a connecting rod.
Parent
Re: (Score:3, Insightful)
We know the human race is not special from a biological POV. For me, that is the limit where arrogance stops. I have a hard time thinking about arrogance in favor of a type of lifeform (nationalism, racism, specism, lifetypism?).
Re:no change of life like us (Score:5, Funny)
Unlike the species of evil gas bags we keep electing...
Parent
Re:no change of life like us (Score:5, Informative)
I'm surprised parent got modded down. There is an enormous amount of evidence to imply lack of extraterrestrial life. Lack of radio waves is the major one, for me, and no one has explained this so far.
Absent an amazing discovery of microbial bacteria or fossils on mars or titan, I think it's very likely that our first indication of life will be the discovery of a planet with a stable oxygen/nitrogen/CO2 atmosphere like our own.
Assuming that all life and civilizations evolve at about the same rate, and all life eventually leads to intelligent life, we're likely to find millions of Alien Life Forms (ALFs) before we find any that are within a few hundred years of us in technology. Why is any more explanation needed?
Parent
Re:no change of life like us (Score:4, Insightful)
Parent
At the risk of starting a flamewar... (Score:4, Interesting)
Parent
Re:no change of life like us (Score:4, Insightful)
Parent
"no chance of life there" (Score:5, Insightful)
Re:"no chance of life there" (Score:5, Interesting)
Parent
Re:"no chance of life there" (Score:5, Funny)
Parent
Re: (Score:2, Interesting)
Re: (Score:2)
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Like there's no water vapor in earth's atmosphere?
According to the article, the planet is gravity-locked, so while the atmosphere may be 1000K, the "dark side" might be "interesting". Look at Mercury - hot enough during the day to melt metals, and cold enough in some spots at night that the air you are breathing right now would be liquid. If it were gravity-locked, the dark side would be the coldest spot in the solar system - colder than Pluto.
While a great discovery, Is this surprising? (Score:4, Interesting)
The most common heteroatomic molecule is likely to be water...
Re: (Score:3, Interesting)
Re: (Score:3, Funny)
Some miscellaneous information: (Score:5, Informative)
Re: (Score:3, Insightful)
HD 189733b is a gas giant planet with 1.15 times the mass of Jupiter and 1.26 its diameter. It orbits its primary in only 2.219 days and in a distance of 0.0313 AU. This is one of the closest planet-star systems known. The planet's surface temperature is 920 kelvin on the poles and 1220 kelvin on the bright side.
Have they come up with a theory on how such planets could form? The last time I read up on this stuff, before they discovered extra-solar planets, the idea was that a star like Sol had an accretion disk that was spread along the solar plane thanks to centrifugal force. The solar wind helped push much of the lighter gases out to the far edges and the heavier, rockier material stayed closer to the inside. Due to the influences of gravity and other forces, you tended to see matter bunch up in concentric circl
No Chance Of Life?!?! WTF? (Score:5, Insightful)
This is a pretty bold statement. Scientist predicted that life couldn't survive in a number of environments on earth, yet it has been found in each one:
1- In lakes frozen hundreds of meters down in antarctica
2- In the dept of the ocean where NO light permeates
3- Next to Volcanic openings in the earths crust were tempuratues are well over 800 degress c
4- In the highly acidic and poisionus ponds in Yellowstone National Park
I am sure that there are more but I can't think of any.
So for some scientist to say that there can't be life, I just have to role my eyes. One thing that I have learned about life is that life will find away. So just because we can't concieve of the possible forms that life might take its a little presumputous for us to assume that it can't exist.
Earth is a small speck in the universe, it doesn't matter if you believe in God or not but to assume that life, as we know it on this planet, is the only form and location of life in the universe is a very ignorant view point.
I am of the firm conviction that as soon as we have the technology to explores these remote and hostile locations we will find things that we haven't even dreamed could exist.
So to get off my little soapbox here; if there is water there is probably life, and just because the conditions on the planet don't fit are current formula for life doesn't mean that our formula is correct.
Re: (Score:2)
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IF NOT (SELECT is_there_life FROM scientist WHERE name = 'Tinetti')
CREATE ROLE eyes;
END IF;
In fairness, I think that's just a bad paraphrasing. "This is a far from habitable world," if you RTA.
Re:No Chance Of Life?!?! WTF? (Score:4, Informative)
"so no chance of life there"
but in the article it clearly says:
"This is a far from habitable world," she adds.
Which means it's a no for us. As well:
"Although the planet is an unlikely candidate in the search for life"
Which is no the same as "no chance"
Your post makes perfect sense but to assume that it is a scientist saying that there can't be life is incorrect.
Parent
Re: (Score:2)
Re:No Chance Of Life?!?! WTF? (Score:5, Insightful)
Mars, we've not even gone to. We've got some rock inspecting toys up there, but that's about it.
Venus, we've never been to there either. Our probes have sampled the atmosphere, that's about it. We still have no idea why it has such a strange rotation.
We have absolutely no credible statement to make about the prevalence of life in the solar system, let alone the universe. But hey, anonymous person on Slashdot, thanks setting us straight.
Parent
Yes, we have been to Venus (Score:3, Informative)
I'm going to be rich. (Score:5, Funny)
I'm seeking venture capital.
I have a friend I'd like you to meet (Score:5, Funny)
Parent
"conclusively"? (Score:3, Interesting)
Re:"conclusively"? (Score:5, Informative)
Here is an excellent article to get you started:
http://astrophysics.suite101.com/article.cfm/wate
And, of course:
http://en.wikipedia.org/w/index.php?title=Spectro
Parent
Why do I suddenly (Score:2)
Let me know when they find beer (Score:4, Funny)
Flawed Proposition (Score:4, Insightful)
The universe is largely transparent, and we can see almost all the way to its privates. The decorations are of the same style and motif throughout, so we can pit our local gravity-well spirlies against theirs and make some reasonable guesses about how far away far is. Since it turns out it's in the neighbourhood of 13 billion lightyears away, I think we can -- as civilized folk -- agree that 13 billion is more than a golybillion shy of infinity.
Check my maths if you're a stickler, but I'm pretty sure I'm on solid ground here.
Space is finite (if gummy), therefore the number of decorations whorled up by our familiar physics is finite, therefore the number of little planety lumps inside of them is finite. Q.E.D.
Parent
Re: (Score:3, Insightful)
Re: (Score:3, Informative)
If the universe isn't macroscopically homogeneous, you wouldn't necessarily see light everywhere. For a degenerate case, imagine a universe such that there is an infinite number of galaxies which are all coplanar. You would have one bright band in the sky, but most of the sky would be dark.
If you assume the universe is infinite in space but finite in time, then i
Re:I can prove there is no life on any other plane (Score:4, Informative)
There can be only a finite amount of life supporting planets.
Just because I feel like nit-picking. If you have an infinite number of planets, you also have an infinite number of planets that support life. Only this is a smaller "infinite" number.
Parent
Re: (Score:3, Funny)
-Mike