Estimate has Milky Way planets at billions

GARCHING, Germany, March 28 (UPI) -- A new estimate of rocky Earth-like planets around red dwarf stars in the Milky Way galaxy puts the number in the billions, European astronomers say.

An international team using observations from the European Southern Observatory's La Silla Observatory in Chile has been searching for exoplanets orbiting red dwarf stars, the most common kind of star in the Milky Way, a release from ESO headquarters in Germany reported Wednesday.

Red dwarfs are faint and cool compared to the sun, but are long lived and very common, accounting for 80 percent of all the stars in the Milky Way.

Astronomers made their observations with a spectrographic instrument known as HARPS on ESO's 12-foot telescope at La Silla.

"Our new observations with HARPS mean that about 40 percent of all red dwarf stars have a super-Earth orbiting in the habitable zone where liquid water can exist on the surface of the planet," team leader of the University of Grenoble in France said.

"Because red dwarfs are so common -- there are about 160 billion of them in the Milky Way -- this leads us to the astonishing result that there are tens of billions of these planets in our galaxy alone."