From “Tens of billions’ of planets in habitable zones” (Yahoo News, Mar 29, 2012), we learn,
“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,” said Xavier Bonfils of the Observatory of the Sciences of the Universe in Grenoble, southeastern France.
“Because red dwarves 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,” he said in an ESO press release issued on Wednesday.
It may be a bit too soon to start selling real estate. They found nine super-Earths in a survey of 102 stars. But so far, super-Earths have been disappointing.
Overall, 763 exoplanets have been found since the first in 1995.
See also: In “10 Billion Earth-Like Planets May Exist in Our Galaxy” (Wired, March 28, 2012), Adam Mann reports,
Until recently, astronomers could only guess at the number of stars with planets around them. Now, with the more than 700 confirmed exoplanets, researchers finally have enough data to begin homing in on the true number.
Astronomers hope to someday build a telescope capable of directly imaging the light from an extrasolar planet and see if they contain the telltale chemicals of life, such as oxygen or methane.
Ah, then it will be time to talk about life on other planets! What’s the timeline?