Saturday, September 3, 2011

A New Planet Capable of Life

The new earth like planet HD85512b
                                            
Have u ever heard about a planet with life except earth. If not then get ready to witness a new planet where we humans can live.
Astronomers have discovered a potentially habitable planet of similar size to Earth in orbit around a nearby star.The unpoetically named HD85512b was discovered orbiting an orange dwarfstar in the constellation Vela. Astronomers found the planet using the European Southern Observatory's High Accuracy Radial Velocity Planet Searcher, or HARPS, instrument in Chile. Radial velocity is a planet-hunting technique that looks for wobbles in a star's light, which can indicate the gravitational tugs of orbiting worlds. The Planet is in the "Goldilocks zone" of space around a star where surface temperatures are neither too hot nor too cold for liquid water to form.


                                    
The star known as Gliese 581 is utterly unremarkable in just about every way you can imagine. It's a red dwarf, the most common type of star in the Milky Way, weighing in at about a third of the mass of the sun. At 20 light years or so away, it's relatively nearby, but not close enough to set any records (it's the 117th closest star to Earth, for what that's worth). You can't even see it without a telescope, so while it lies in the direction of Libra, it isn't one of the shining dots you'd connect to form the constellation.The discovery caps an 11-year effort to tease out information from instruments on ground-based telescopes that measure minute variations in starlight caused by the gravitational tugs of orbiting planets.Planet G -- the sixth member in Gliese 581's family -- orbits right in the middle of that system's habitable region, where temperatures would be suitable for liquid water to pool on the planet's surface.
Size Comparision
                                           

The planets have all been found by the Doppler method: as they orbit the star, the tug on it .This causes a shift in the wavelength of emitted light from the star. The mass of the planet, its distance from the star, and the shape of the orbit all determine how the light shifts, which is how astronomers found those properties of the new planet.There are some things we can speculate on with some solid footing. The orbital period of 37 days puts it pretty close to the star – since the star is a red dwarf, it’s cooler than the Sun, so being closer doesn’t necessarily mean you overheat. But it does mean the star exerts strong tides on the planet,which have the effect of slowing the planet's rotation until it equals the orbital period. This has almost certainly happened to this planet, so in other words, one day on this planet = one year, and the planet always shows the same face to its star like the Moon does to the Earth.But perhaps the most interesting and exciting aspect of all this is what it implies. The Milky Way galaxy is composed of about 200 billion stars, and is 100,000 light years across. The fact that we found a planet that is even anything like the Earth at all orbiting another star only 20 light years away makes me extremely optimistic that earthlike planets are everywhere in our galaxy. 20 light years is practically in our lap compared to the vast size of our galaxy, so statistically speaking, it seems very likely it’s not unique. I don’t want to extrapolate from a data set of two (us and them), but if this is typical, there could be millions of such planets in the galaxy.
                                                         
So we have yet not much discovered much about the planet but it can be a habitable planet or an other world where also different kinds of species like us can survive.

[via Discover Magazine]

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