A new estimate of the number of habitable planets orbiting the most common type of stars in our galaxy could have huge consequences for the search for life.
According to a recent study, tens of billions of planets around red dwarfs are likely capable of containing liquid water, dramatically increasing the potential to find signs of life somewhere other than Earth.
Red dwarfs are stars that are fainter, cooler and less massive than the sun. These stars, which typically also live longer than Class G stars like the sun, are thought to make up about 80 percent of the stars in the Milky Way, astronomers have said.
A second look
Red dwarfs generally have not been considered viable candidates for hosting habitable planets. Since red dwarfs are small and dim, the habitable zone surrounding them — the region where an orbiting planet's surface water can remain liquid — is relatively close to them.
"The habitable zone would be very, very small. Consequently, the chances that you would actually find any planet at the right distance from the sun to be attractive to life was likely to be small, too," said Seth Shostak, a senior astronomer at the Search for Extraterrestrial Intelligence Institute in Mountain View, California.
But the study, based on data from the European Space Agency's HARPS spectrograph in Chile, used a sample of 102 red dwarfs to estimate that 41 percent of the dim stars might be hiding planets in their habitable zone.
"The number of habitats might increase by a factor of 8 or 10," Shostak told SPACE.com.