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First Exoplanet Atmospheres Analyzed
deblau writes "NASA's Spitzer Space Telescope has captured for the first time enough light from planets outside our solar system, known as exoplanets, to identify signatures of individual molecules in their atmospheres. The landmark achievement is a significant step toward being able to detect possible life on rocky exoplanets and comes years before astronomers had anticipated."
All the extra solar planets that have been found so far are large gas giant type planets.
Our telescopes aren't good enough (yet) to detect small earth size rocky planets.
While spectographic analysis of these planets atmosphere is interesting, it does not give us information about the possiblity of life (as we know it, Jim) since these aren't the places we would find life in this solar system either. Maybe these other planetary systems do include rocky planets, or moons (like titan and europa ) that could be candidates for some form of life, but we wouldn't find that out by looking at the atmospheres of JUpiter and Saturn
I figured somebody better follow the joke up with some clarification. The optics on Spitzer, like Hubble, aren't focused that close. Plus it's infrared. Skin complexion would look like crap.
Also, they aren't directly seeing the planet. I don't know if Spitzer's cameras could theoretically resolve it, but I do know it can't pick it out of the glare from its star. The method is to use a spectrograph and note really carefully the spectra of light received from the observation. When the planet, which is emitting light at different wavelengths depending on the molecules present, goes behind the star, this spectra changes ever so slightly. From this you know which portions of the spectra are from the star and which are from the planet, and you can deduce the molecules based on characteristic spectral lines.
This is very much like colors on an LCD monitor. Let's say you have a switch that will let you turn off one pixel of a triad (the triad being the red, green, and blue pixels that make up a visible pixel), but you don't know what color it is. If you see a yellow pixel, you know there is actually a red pixel and green pixel turned on right next to each other, even though your eye can't resolve them. You flip the switch and the visible pixel turns red, so you know the pixel you control is green. The colors of the pixels are analogous to the molecules on the planet versus the star. The pixel you can control is like the planet, but instead of a switch it goes behind the star.
Since the article apparently likes big numbers over useful units, the 370 and 904 trillion mile figures for the distances to the two observed targets are equal to 63 and 153 light years respectively.
These data were taken in the mid-infrared, where the contrast between the star and the planet is not as great --- only about 200--300:1, instead of 10^6--10^10 to 1 in the optical/near-IR.
If you RTA, they mention that Hubble was only able to identify elements in the atmosphere and was using a different technique. Spitzer is able to make out molecules.