A New Earth-like Planet; "Aliens home..??"

'Is there life anywhere else?'

Astronomers have discovered the most Earth-like exoplanet yet. The planet, the smallest yet discovered, orbits the red dwarf Gliese 581 at a distance one fourteenth of that from Earth to the sun; its year is just 13 days long. However, because the star is so much cooler and less luminous than our own sun, the so-called habitable zone, where planets can carry liquid water, is much nearer the star. As we know, liquid water is critical to life. Moreover, its radius should be only 1.5 times the Earth's radius, and models predict that the planet should be either rocky - like our Earth - or covered with oceans. Scientists made the discovery using the Eso 3.6m Telescope in Chile.

The planet orbits the faint star Gliese 581, which is 20.5 light-years away in the constellation Libra. Gliese 581 c was identified at the European Southern Observatory (Eso) facility at La Silla in the Atacama Desert. The team making the discoveries used the HARPS (High Accuracy Radial Velocity for Planetary Searcher), perhaps the most precise spectrograph in the world. It can spot signals - variations in the velocity of a star - that fall far below the "noise" threshold of most spectrographs. The instrument can measure tiny changes in the velocity of a star as it experiences the gravitational tug of a nearby planet. Professor Glenn White at the Rutherford Appleton Laboratory is helping to develop the European Space Agency's Darwin mission, which will scan the nearby Universe, looking for signs of life on Earth-like planets.