There's a new paper in Nature announcing the detection of water vapor in the atmosphere of a "hot Jupiter" orbiting a distant star. There's also a story on Physics Web and a press release from the Spitzer Telescope group, if you'd like some stuff you can read without a subscription to Nature.
The idea here is that the planet passes between its star and Earth every couple of days, causing a dimming of the light from the star. The researchers looked at the first part of that dimming, which is when the light is passing through the edge of the atmosphere, and measured the amount of light in a few different ranges of wavelengths in the infrared region of the spectrum. One of these showed less absorption than the others, which is attributed to the presence of water vapor in the atmosphere of the planet, absorbing light in the other two bands.
Of course, Steinn has more, including one very good general comment:
Good solid science, pushing what is doable with current instruments that we should remember were not designed to do this science, it is serendipitous that this sort of data can be squeezed out of them since they were spec'd to do different but related science.
Yet another example of the almost infinite ingenuity of scientists. Go, us.
Fantastic. Think there are aliens?