Earth-like planets — and aliens? — may be closer than we thought
Posted in: Science
Confirming what “Doctor Who” fans have long suspected, astronomers at the Harvard-Smithsonian Center for Astrophysics (CFA) have found that Earth-like planets, and possibly alien life, may be right in our celestial backyard.
The closest Earth-like planet could be as little as 13 light-years away, the scientists said in a report released Wednesday.
That’s still a distance of about 76 trillion miles, but in the context of our vast universe, it is practically right next door.
The working definition of an Earth-like planet is one that is small, rocky and warm enough for liquid water to exist on its surface. Scientists have pegged these types of planets as a starting place to look for extraterrestrial life forms.
For this report, the scientists analyzed data collected by NASA’s Kepler telescope, which is pointed at 158,000 target stars in a portion of the Milky Way galaxy to see if they support habitable planets. They limited their investigation to just red dwarf stars, which are one-third as large as our sun, one-thousandth as bright and make up 3 out of every 4 stars in our galaxy.
They found that 6% of red dwarf stars have planets that are both the right size and temperature to be Earth-like, and from there they extrapolated that the closest Earth-like world is likely 13 light-years away.
Of course, a planet roughly the same size and temperature as Earth that orbits a red dwarf would still be very different from Earth. The planet would have to be much closer to its star than we are to the sun in order for it to be warm enough to support liquid water.
And because red dwarf stars live much longer than sun-like stars, the scientists point out that it is also possible that the planets around them are much older than Earth, and could potentially have more evolved life than on our own planet.
Anyone else getting goosebumps?
“You don’t need an Earth clone to have life,” lead author Courtney Dressing said in a statement.
— Deborah Netburn