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Astronomers have measured gases in the atmosphere of a "super-Earth" exoplanet, 55 Cancri e:
For the first time, astronomers have managed a direct measurement of the gases present on a "super-Earth" planet orbiting an alien star. They found evidence for hydrogen and helium in its atmosphere, but no water. Called 55 Cancri e, the world is twice the size of Earth and eight times the mass - but orbits unusually close to its host star, with an 18-hour year and surface temperatures above 2,000C. The UK team published their findings in the Astrophysical Journal.
"This is a very exciting result because it's the first time that we have been able to find the spectral fingerprints that show the gases present in the atmosphere of a super-Earth," said Angelos Tsiaras, a PhD student at University College London and the first author of the paper. "Our analysis of 55 Cancri e's atmosphere suggests that the planet has managed to cling on to a significant amount of hydrogen and helium from the nebula from which it formed."
55 Cancri e is at least 48% as massive as Neptune. The exoplanet is about 40 light years away from Earth.
Detection of an atmosphere around the super-Earth 55 Cancri e
(Score: 5, Interesting) by Covalent on Wednesday February 17 2016, @06:43PM
Obviously this is not a candidate for habitability. The only reason we can see its atmosphere is because it is literally glowing (2000C is mighty hot!)
But the real goal is to do absorption spectroscopy using a planet's atmosphere. When an exoplanet in the habitable zone passes in front of its star, a small amount of light should be absorbed preferentially by the atmosphere. The difference here is incredibly tiny, but in principle it should be possible to detect which gases constitute the planet's atmosphere.
An Earth-sized planet with free oxygen in its atmosphere is the most likely evidence of extraterrestrial life we are likely to get. There do not seem to be any geological processes which can create free oxygen in measurable quantities...only life seems to do that.
There might be life on planets even without free oxygen in the atmosphere, but the oxygen is the smoking gun.
And to think my physics teacher told me I would never live to see extrasolar planets discovered...in 1993. :-D
You can't rationally argue somebody out of a position they didn't rationally get into.
(Score: 2) by takyon on Wednesday February 17 2016, @07:00PM
Wow, good stuff. Probably didn't think too much of gravity waves either.
I'll just dump this here:
http://www.theatlantic.com/technology/archive/2012/10/atlast-the-gargantuan-telescope-designed-to-find-life-on-other-planets/263409/ [theatlantic.com]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by Covalent on Wednesday February 17 2016, @07:52PM
Yeah, I tell my own chemistry and physics students that story and then ask them to call me out whenever I say something isn't possible!
Also, this:
http://www.scientificamerican.com/article/the-truth-about-exoplanets/ [scientificamerican.com]
You can't rationally argue somebody out of a position they didn't rationally get into.
(Score: 2) by bob_super on Wednesday February 17 2016, @08:09PM
> And to think my physics teacher told me I would never live to see extrasolar planets discovered...in 1993. :-D
I've always wondered why anyone would think there are no other planets, or life*, in the universe. I guess we want to be special.
Still, I'm pretty amazed at how quickly we went from public doubters, to discovering them so fast we don't even try to cute-name them.
*: the existence of "life" in the broadest sense imaginable, is pretty certain (to me). Earth-like carbon-based life is a much much much narrower window, though still highly likely statistically.
(Score: 3, Interesting) by fritsd on Wednesday February 17 2016, @08:45PM
I think it's not just that there's free oxygen in the atmosphere in general.
There's loads of oxygen on Earth: water, silicon dioxide (sand), aluminium-iron-calcium-magnesium oxides (rocks), etc.
From a great distance, I'd imagine our planet is interesting, because its chemistry looks far-out-of-equilibrium.
For instance, why isn't there a lot more nitrogen oxides in the air? Over the aeons surely most of the free oxygen would have reacted with the nitrogen in the air (haven't bothered to check whether that's exothermic).
And then there are traces of CO2 (normal) and CH4 (NOT normal). Why is there traces of methane in our atmosphere? COW FARTS! (and other sources).
That should have all reacted straightaway with the oxygen, unless there is, yet again, a mechanism to replenish this steady-state out-of-equilibrium situation.
Here we get to the more "chaos theory" aspects of thermodynamics (cue Jurassic Park music):
According to Ilya Prigogine, steady-states can't go on forever. If they're far out of equilibrium, there must be something to sustain them, and when that process finishes, the steady-state returns to normal equilibrium. Call it rotting if you like.
According to Maturana an Varela, if I remember correctly which I surely don't, systems that maintain and replenish themselves and their surroundings against the thermodynamic equilibrium, can be called "autopoietic", i.e. they "make themselves".
Then we're already quite a lot closer to the visible aspects of life: (a) it can create more of itself in its surroundings, and (M.+V.) (b) it modifies its surroundings in such a way that it can more easily create more of itself. Because evolution. Hit me if I remember it wrong.
If we saw spectral lines of free oxygen on reflected light from Saturn's moon Titan, then I'd agree with you that surely with Titan's atmosphere filled with a reducing atmosphere of Nitrogen and Methane, Oxygen would be well odd.
In our own case, I think the E.T.s would just conclude we had a lot of surplus Oxygen lying around -- until they saw molecular methane IR lines in our oxydating atmosphere, after which I'd hope they'd exclaim: "Holy cow!"
I always thought that would be cool, until I saw the XKCD cartoon about camouflage which dampened my ET enthusiasm: http://www.xkcd.com/1377/ (Fish) [xkcd.com]