Using
data from Nasa's Kepler space telescope, Astronomers argue that one in
five stars like the Sun hosts Earth-sized world located in the
"habitable zone".
This zone is the region around a star where temperatures allow for water - a key ingredient for life - to stay liquid at the surface.
Last week, astronomers announced the discovery of an Earth-sized, rocky planet orbiting its star at a hundredth of the distance between the Earth and the Sun.
Temperatures on this world would reach between 2,000C and 2,800C, with much of the dayside molten, meaning there would be little chance for life here.
But team members cautioned that even finding Earth-sized planets in the habitable - or "Goldilocks" - zones of their stars was no guarantee these worlds would be hospitable to life.
Researchers had previously combed through some 42,000 stars and discovered 600 likely planets. Of these, 10 were both Earth-sized and located at a distance that was just right for liquid water to persist on the surface.
However, the team then corrected for planets that might have been missed by software designed to sift through the Kepler data for planet signatures. This process involved introducing fake planets into the data.
Accounting for these missed worlds, as well as the fact that only a small fraction of planets are oriented so that they cross in front of their host star as seen from Earth, the astronomers were able to estimate that 22% of all Sun-like stars in the Milky Way have Earth-sized planets in the habitable zone.
This zone is the region around a star where temperatures allow for water - a key ingredient for life - to stay liquid at the surface.
Last week, astronomers announced the discovery of an Earth-sized, rocky planet orbiting its star at a hundredth of the distance between the Earth and the Sun.
Temperatures on this world would reach between 2,000C and 2,800C, with much of the dayside molten, meaning there would be little chance for life here.
But team members cautioned that even finding Earth-sized planets in the habitable - or "Goldilocks" - zones of their stars was no guarantee these worlds would be hospitable to life.
Researchers had previously combed through some 42,000 stars and discovered 600 likely planets. Of these, 10 were both Earth-sized and located at a distance that was just right for liquid water to persist on the surface.
However, the team then corrected for planets that might have been missed by software designed to sift through the Kepler data for planet signatures. This process involved introducing fake planets into the data.
Accounting for these missed worlds, as well as the fact that only a small fraction of planets are oriented so that they cross in front of their host star as seen from Earth, the astronomers were able to estimate that 22% of all Sun-like stars in the Milky Way have Earth-sized planets in the habitable zone.
0 comments:
Post a Comment