Billions more across the galaxy - stand by for aliens
By Lewis Page
Posted in Space, (The Register) 28th March 2012 14:58 GMT
In an announcement with massive consequences for the human race, astronomers say there are “probably about one hundred” planets within just 30 light-years of our solar system which could support life along Earthly lines. By their calculations, there are tens of billions of such worlds in our galaxy, suggesting that even if life is very rare it is bound to have arisen elsewhere.
The new astroboffinry involves examination of red dwarf stars - the most common type of star found in the galaxy - using the HARPS spectrograph on the 3.6-metre telescope at the La Silla Observatory in the mountains of Chile. The HARPS team surveyed 102 red dwarfs over a six-year period, discovering nine “super-Earths” (planets with masses between one and ten times that of Earth, thus probably rocky planets as opposed to gaseous ones). They were able to measure planetary mass and orbital distance from the parent stars.
The methods used could discern only a proportion of planets which exist, and the team’s calculations applied to the results indicate that in general approximately 40 per cent of the red dwarfs in the Milky Way should possess an Earthlike, rocky planet lying within their “habitable zone” - that is orbiting at such a distance as to permit the existence of liquid water on the planet’s surface.
“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,” enthuses Xavier Bonfils, lead boffin on the investigation.
According to a statement issued by the European Southern Observatory announcing the research:
As there are many red dwarf stars close to the Sun the new estimate means that there are probably about one hundred super-Earth planets in the habitable zones around stars in the neighbourhood of the Sun at distances less than about 30 light-years [ten parsecs].
Nw Astroboffinry is now my band name.