Nearby trio exoplanets orbiting small, cool star.
SAN FRANCISCO (AA) - An international team of scientists reported Monday that they have discovered three potentially habitable Earth-sized planets orbiting a relatively close star.
The trio of exoplanets -- planets outside of the solar system -- likely host conditions that are hospitable to life, scientists believe. They orbit a small, cool star known as TRAPPIST-1.
Temperatures at the surface of the planets, according to the report, are right for liquid water to pool. TRAPPIST-1 is 40 light-years away, roughly equivalent to 380 trillion kilometers (235 trillion miles), which is close enough for scientists to observe their atmospheres with current technology.
The discovery was published in the journal Nature by scientists working at the University of California, San Diego; Massachusetts Institute of Technology and the University of Liège in Belgium.
"The kind of planets we've found are very exciting from the perspective of searching for life in the universe beyond Earth," study participant Adam Burgasser of the University of California San Diego said in a statement.
While many Earth-like exoplanets have been discovered in recent years, most are hard to research because they orbit bright stars similar to the sun.
The brightness makes it extremely difficult to accurately locate and study the planets over time. Since the newly discovered planets orbit a dim star, however, they are exceedingly valuable to scientists.
"These planets are so close, and their star so small, we can study their atmosphere and composition, and further down the road, which is within our generation, assess if they are actually inhabited," according to co-author Julien de Wit of MIT. "All of these things are achievable, and within reach now. This is a jackpot for the field."
Most exoplanets scientists can observe in any detail are huge and have atmospheres similar to Jupiter -- so they are not habitable for life as we know it.
With the newly-discovered threesome, scientists can study Earth-like worlds in much closer detail than ever before, even though visiting with a spacecraft would be decades away.