Friday, April 18, 2014

No signs of life yet - DailyTech



No signs of life yet

The question of whether life exists on other planets will always remain a curiosity as we continue venturing into space. Movies like "E.T." and "Alien" are just a couple examples of our fascination with such an idea. 

NASA, as our government space agency, is obviously curious as well. But we could be a step closer to answering such questions as NASA has found the first Earth-Size planet in the 'habitable zone' of another star. 

According to NASA, the Kepler Space Telescope found an Earth-sized planet orbiting a star in the habitable zone, which is the range of distance from a star where liquid water might collect on the surface of an orbiting planet -- meaning the possibility of life. 

The new planet has been dubbed Kepler-186f, and it is about 500 light-years from Earth in the constellation Cygnus. It orbits a star -- which is classified as an M d! warf, or red dwarf -- half the size and mass of our sun.

Kepler-186f orbits its star once every 130-days and receives one-third the energy from its star that Earth gets from the sun. This puts it near the outer edge of the habitable zone. 

 

The brightness of its star at high noon is only as bright as Earth's sun appears about an hour before sunset. Further, NASA isn't quite sure yet, but it believes Kepler-186f's surface rocky.
 


A sketch of Kepler-186f [SOURCE: NASA]


Kepler-186f isn't alone over there, though. It has four companion planets, called Kepler-186b, Kepler-186c, Kepler-186d, and Kepler-186e. They make their way around their sun every four, seven, 13, and 22 days respectively, and they're too hot for any life to exist on them. 
 

Size is key here. While planets have been discovered in the habitable zone before, they haven't been the same size as Earth, which makes it harder for us to understand fully. The four companion planets, for example, all measure less than 1.5 times the size of Earth. Also, previously discovered planets in the habitable zone were were at least 40 percent larger in size than Earth. 

With Kepler-186f being about the same size as Earth, we can have a clearer idea of behaviors, topography, etc. But as of right now, its mass and composition are unknown. 

Unfortunately, whether it contains other life is also unknown at this time. But it's always a worthy consideration when stumbling upon new planets in what are considered "habitable" areas. 

"The discovery of Kepler-186f is a significant step toward finding worlds like our planet Earth," said Paul Hertz, NASA's Astrophysics Division director at the agenc! y's headquarters in Washington. "Future NASA missions, like the Transiting Exoplanet Survey Satellite and the James Webb Space Telescope, will discover the nearest rocky exoplanets and determine their composition and atmospheric conditions, continuing humankind's quest to find truly Earth-like worlds."

Source: NASA

Source : http://www.dailytech.com/NASA%2BFinds%2BHabitable%2BZone%2BPlanet%2BSized%2BSimilar%2Bto%2BEarth/article34750c.htm