Friday, May 24, 2013
The Associated Press
CAPE CANAVERAL, Fla. - Earth-like worlds may be closer and more plentiful than anyone imagined.
This rendering shows a planet with two moons orbiting in the habitable zone of a red dwarf star.
The Associated Press
Astronomers reported Wednesday that the nearest Earth-like planet may be just 13 light-years away -- or some 77 trillion miles. That planet hasn't been found yet, but should be there based on the team's study of red dwarf stars.
Galactically speaking, that's right next door.
If our Milky Way galaxy were shrunk to the size of the United States, the distance between Earth and its closest Earth-like neighbor would be the span of New York's Central Park, said Harvard University graduate student Courtney Dressing, the study's lead author.
"The nearest Earth-like planet is simply a stroll across the park away," she said.
Small, cool red dwarfs are the most common stars in our galaxy, numbering at least 75 billion.
The Harvard-Smithsonian Center for Astrophysics team estimates 6 percent of red dwarf stars have Earth-like planets. To qualify, the planet must be roughly the size of Earth and get as much light from its star as Earth does from the sun.
This high rate of occurrence should simplify the search for extraterrestrial life.
As the report's co-author, David Charbonneau, noted, he's an astronomer, but hopes to become a biologist if that search succeeds.
These planetary candidates are quite different than Earth because of the differences between their red dwarf stars and the sun, Charbonneau told reporters.
Because the red dwarfs are so much smaller, potentially habitable planets would need to orbit much closer than the Earth does to the sun. They likely would be rocky
Red dwarf stars also can be old -- far older than our sun -- which means their planets could be much older than Earth and their potential life forms much more evolved.
"It's right within reach and future efforts will put scientists hot on the trail of finding life elsewhere in the galaxy," said California Institute of Technology astronomer John Johnson.