Found the presence of water in five alien worlds
Thanks to the Hubble Space Telescope has been possible to scan the atmosphere of many exoplanets. And confirm the existence of the precious liquid in five of them. A NASA video explains how.
The coming year could bring the discovery of an Earth -like. Potential candidates identified so far lacking, certain confirmations of the presence of fluid essential for life, water. To find its traces, however, we must first study the atmospheres of alien worlds, far from easy undertaking, given the vast distances that separate us from them.
Thus, two groups of scientists have decided to use the Hubble Space Telescope to peer into the atmosphere tens of extrasolar planets in search of water. The hunt is successful: five planets have been found that show the unmistakable sign of the precious liquid. Three of them, WASP- 12b, WASP- 17b and WASP- 19b orbiting the same star even while HD209458b and XO -1b are located around the eponymous stars but in another region of space. They are all “hot Jupiters,” that is as large as or more than Jupiter and revolve close to the host star. They are therefore not suitable to host life, but the discovery of water in their atmospheres is still an outstanding result because” allows for the first time to establish a relationship between the amount of water present with the peculiar characteristics of each exoplanet, for example size and temperature, and compared with each other, “says planetary scientist at NASA Avi Mandell, lead author of the paper describing the discovery on ‘ Astrophysical Journal, December 3.”Also brings us closer to a method to thoroughly investigate the composition of exoplanets” adds the scientist.
But why is it so difficult to detect the presence of water in the alien worlds? He explains this NASA video: to analyze the atmosphere of an extrasolar planet transits that you have to wait in front of their star, when part of the light of the star is absorbed by the molecules present in atmospheric gases. The spectrum of light that reaches the telescope is so obscured in the wavelengths that each molecule absorbs different: it is as if each chemical leave their fingerprints are unique and “cataloged”.
The Hubble observations, made in the infrared, have shown unequivocal “signature” of water molecules in the five giant planets. But the track was very weak, which did suggest a layer of fog that surrounds them. And just like the haze softens colors in a photograph, in the same way alter or obscure the signal molecules. “With these new Hubble observations, however, we realized that the planets are surrounded by misty atmosphere are very common and this can hide the actual presence of water in many alien worlds,” says Heather Knutson, astrophysics at Caltech.