A team of astronomers, including two from San Diego State University, today announced the remarkable discovery of a five-planet system some 1,200 light years away with two super-Earth-sized planets that could support life as we know it.
The two planets, which both have what astronomers call "endless oceans," are the most Earth-like that researchers have found to date in terms of both size and temperature, according to William Welsh, professor of astronomy at SDSU and co-author of the study published today in Science.
"These planets are unlike anything in our solar system. They have endless oceans," Lisa Kaltenegger, an astronomer at the Max Planck Institute for Astronomy and the Harvard-Smithsonian Center for Astrophysics, said in a statement today. "There may be life there, but could it be technology-based like ours?"
In an era when scientific research too often gets thrown under the bus both by politicians and the media, this is exciting news that deserves our attention. I hope it's talked about in science classes across the nation tomorrow. Funding for this work was provided in part by NASA and the National Science Foundation.
“The composition of the planets is not known, but it is possible they are rocky. If so, and if liquid water is present, there’s a chance these planets could harbor life,” said Welsh. “At only 60 percent and 40 percent larger than the Earth, these two super-Earth planets are the smallest planets yet discovered in the habitable zone.”
"These two planets are our best candidates for planets that might be habitable," said Bill Borucki, a space scientist at NASA's Ames Research Center who is the principal investigator for the $600 million Kepler mission.
It's estimated that he new planetary system, which is located in the constellation Lyra, is approximately 7 billion years. That's somewhat older than the solar system.
The planetary system, known as Kepler-62 (right), contains five planets, ranging from 0.54 to 1.95 times the size of the Earth. The innermost planet orbits its star every 5.7 days, while the outer one takes 267 days to complete one orbit.
The star itself is smaller and fainter than Earth’s sun with 69 percent of the sun’s mass, 64 percent of the sun’s radius, and only 21 percent of the sun’s brightness.
“Since Kepler-62’s star is only a fifth as luminous as our sun, the planets in its habitable zone have to orbit much closer to it, resulting in a much shorter year," said co-author Jerome Orosz, associate professor at SDSU. "For the two planets in the habitable zone, Kepler-62e and Kepler-62f, this is 122 and 267 days."
Welsh and Orosz have been working on the Kepler mission since 2008, contributing their expertise to the discovery of dozens of new planets. “The Kepler mission continues to be a great success,” said Orosz.
Added Welsh, "All five planets are smaller than twice the size of the Earth, and one is even the size of Mars,.This is an absolute gem of a planetary system."