Carbon Dioxide and Water Found On Exoplanet 151
Off the Rails writes "The BBC reports that evidence has been found for both water vapour and carbon dioxide on a planet 63 light years away. The planet is a 'hot Jupiter' with a surface temperature of 1173K and an orbital period of just 53 hours. The gases were found spectroscopically once its orbit had been deduced from observation. NASA hailed the news as proof that Kepler will be able to do its job of finding planets capable of supporting life." Wikipedia also has an entry on the planet, dubbed HD 189733b.
Re:1173K! (Score:3, Informative)
1175 K = 902 C = 1655.6 F
Really damn hot.
"That's LORD Kelvin to you!" - Adam Savage
Re:Doxide? (Score:3, Informative)
No, I guess I foolishly assumed it was a spelling error. Then I googled it. Slashdot has the 3rd result (as of now). There's no wikipedia entry. Googling "doxide definition" gives no relevant results. Please, enlighten me on this definition. It appears you are in the know on this obscure term.
Capable of supporting life? (Score:3, Informative)
NASA hailed the news as proof that Kepler will be able to do its job of finding planets capable of supporting life.
I guess all you need to support life these days is water vapor and carbon dioxide. Never mind that the planet is hotter than the surface of some stars.
Re:Um No. (Score:5, Informative)
I'm of the opinion that spending billions of dollars on searching for ET life is silly, but in this article's [or the summary thereof] defense, it didn't say THIS planet was habitable. My reading was that they simply proved (presumably) that they were able to find out if water and CO2 exists on a planet.
Re:Capable of supporting life? (Score:5, Informative)
The temperature of a gas giant has little meaning since it increases with depth.
Since there is little to no "surface" there are just different temperatures at different altitudes.
For example, there is perfectly comfortable weather on Venus at a certain altitude, around 50 km... just not at the surface.
Kepler is not Hubble's replacement (Score:5, Informative)
Kepler will be a small telescope (about 1 meter) in orbit, with the sole mission of looking at a few fixed areas on the sky and searching for planets by the transit method: take thousands of pictures and look for stars which become dimmer for a few hours due to a planet crossing their disks. This small mission will launch in spring 2009 and is NOT a replacement for HST.
The James Webb Space Telescope (JWST) is Hubble's replacement. It will be much larger (with a mirror around 6.5 meters in diameter) and carry out many, many different types of observations. This mission will launch, uh, some time around 2013, if all goes well.
Re:Capable of supporting life? (Score:3, Informative)
As for hotter than the surface of some stars? That's a bit misleading. There are thermal vents on our planet hotter than the surface of some stars if you count the same stars you are referring to - and that's not exactly mind-blowing.
In other news. Temperatures hotter than the surface of stars [recipesource.com] used in everyday dessert cooking!
CO2, if present, is the real news (Score:2, Informative)
Carbon dioxide, on the other hand, is a surprise: at the temperatures and pressures encountered in an exoplanet atmosphere of this type, all carbon should be present as methane (if cool enough) or carbon monoxide. Giant planet atmospheres are generally far too hydrogen-rich for CO2 to form in any appreciable quantity. So its detection requires an extra-ordinary explanation for its origin.
Here [arxiv.org] is a Nature preprint from the same research group, describing H2O, CH4, and CO detection. I was hoping to find a research article (and not just a news story or press release) describing CO2 detection, but haven't found any yet...
Re:Capable of supporting life? (Score:5, Informative)
Kepler is a space telescope designed to look for planets that transit their stars from our point of view.
It's been well established by ground telescopes that you can detect planets, including fairly small planets and ones in quite distant orbits using this method.
It's now been established that you can get reasonable spectra of transiting planets through this subtraction method.
Thus, Kepler, which detects planets that transit their stars, should be able to detect planets that are the right size and in the right orbit for life, and should ALSO be able to obtain spectra so their composition can be determined.
Thus, Kepler should be able to detect planets where life is possible, or even likely.
Re:Um No. (Score:5, Informative)
Your understanding is incorrect.
Kepler is designed to detect planets that transit their parent stars. That is, the planet passes directly in front of the star from our point of view. That causes the perceived brightness of the start to decrease a little when the planet passes in front.
Kepler is expected to be able to detect Earth-sized planets. Since the planet passes directly in front of the star, you can measure changes in the spectra from the system as the planet passes in front. By subtracting the star - planet and the star + planet measurements, you can get an idea of the composition of the planet's atmosphere.