By analyzing publicly available Kepler data, CfA astronomers identified 95 planetary candidates circling red dwarf stars. Of those, three orbit within the habitable zone (marked in green) — the distance at which they should be warm enough to host liquid water on the surface. Those three planetary candidates (marked with blue dots) are 0.9, 1.4, and 1.7 times the size of Earth. In this graph, light received by the planet increases from left to right, and therefore distance to the star decreases from left to right. Planet size increases from bottom to top. Image released Feb. 6, 2013.
CREDIT: C. Dressing (CfA)

4.5 Billion ‘Alien Earths’ May Populate Milky Way

by Mike Wall, SPACE.com Senior Writer
Date: 06 February 2013 Time: 11:01 AM ET

Billions of Earth-like alien planets likely reside in our Milky Way galaxy, and the nearest such world may be just a stone’s throw away in the cosmic scheme of things, a new study reports.

Astronomers have calculated that 6 percent of the galaxy’s 75 billion or so red dwarfs — stars smaller and dimmer than the Earth’s own sun — probably host habitable, roughly Earth-size planets. That works out to at least 4.5 billion such “alien Earths,” the closest of which might be found a mere dozen light-years away, researchers said.

“We thought we would have to search vast distances to find an Earth-like planet,” study lead author Courtney Dressing, of the Harvard-Smithsonian Center for Astrophysics (CfA), said in a statement. “Now we realize another Earth is probably in our own backyard, waiting to be spotted.”

Read more: 4.5 Billion 'Alien Earths' May Populate Milky Way | Space.com.

Home           Top of page