Miťrcoles 1 de Agosto de 2007, Ip nļ 201

Scientists Find Evidence of Water on Planet
Astronomers have found what they say is the best evidence yet for water, or at least steam, in the atmosphere of a planet around another star, but itís a sure bet there is no one there to drink it.

The planet, known as HD 189733b, is slightly larger than Jupiter and orbits a star about three million miles away in the constellation Vulpecula. Earlier this year, the Spitzer Space Telescope measured the planetís temperature at 1,300 degrees Fahrenheit and suggested it was bone dry, to the consternation of theorists who say water should be fundamental in planet formation.

Now a team, which also used the Spitzer telescope, has re-examined the planet as it passed in front of its star. The earlier observations had been made when the planet passed behind its star.

In the new arrangement, starlight passing through the planetís atmosphere was absorbed at infrared wavelengths characteristic of water, suggesting that there is water on the planet if you know how to look for it.

The team, led by Giovanna Tinetti of the European Space Agency and University College, London, reported its work today in Nature.


  12/07/2007. The New York Times.