A multi-national team of Swiss, French and Portuguese scientists have made a very important discovery: The first potentially habitable planet outside of our solar system.
The newly discovered extrasolar planet is the smallest yet discovered. It is estimated to have a radius 50% bigger than the Earth, so gravity on it would be about twice as strong as it is here, and it orbits a red dwarf called Gliese 581 which is 20.40 light years away (relatively close to us) in the constellation Libra.
The exoplanet is 14 times closer to its star than the Earth is from the Sun and so its year – a full orbit around the star – is only 13 Earth days long. But the good news is that since the red dwarf is “smaller [one third of the mass] and cooler than the Sun, the planet nevertheless would lie in its habitable zone—the region around a star with suitable temperatures for liquid water.”
Average temperatures on this “super-Earth” lie between 0 and 40 degrees Celsius (32 to 104 degrees Fahrenheit), “and water would thus be liquid,” said Stéphane Udry of Switzerland’s Geneva Observatory, lead author of a paper reporting the result. “Models predict that the planet should be either rocky—like our Earth—or covered with oceans,” he added. […]
“Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extra-terrestrial life. On the treasure map of the Universe, one would be tempted to mark this planet with an X.”
All of this thanks to what seems to be an amazing instrument:
The find was possible thanks to an instrument known as a spectrograph on the European Southern Observatory’s 3.6-meter telescope at La Silla, Chile, according to the group. The instrument, called the High Accuracy Radial Velocity for Planetary Searcher, is touted as one of the most successful tools for detecting exoplanets to date.
The instrument measured wiggles in the star’s motion corresponding to velocity changes of just two to three meters per second—the speed of a brisk walk, according to the Geneva Observatory’s Michel Mayor, principal investigator for the instrument. Given the results so far, “Earth-mass planets around red dwarfs are within reach” of discovery, he predicted.
The arrow marks the approximate location of the red dwarf star Gliese 581 with respect to the constellation Libra visible in the southern sky. Image credit: World-Science.net
- Distant planet judged possibly habitable
- First habitable Earth like planet outside Solar System discovered