A newly-discovered planet may have liquid water on its surface, according to a report published today by an international team of astronomers. The planet was discovered orbiting Kapteyn’s Star, a red dwarf only 13 light years away, making it the 25th closest star to our sun.
“Finding a stable planetary system with a potentially habitable planet orbiting one of the very nearest stars in the sky is mind blowing,” said Pamela Arriagada, an author on the study. “This is one more piece of evidence that nearly all stars have planets, and that potentially habitable planets in our galaxy are as common as grains of sand on a beach.”
Two planets were discovered orbiting the star, but the one dubbed Kapteyn b has sparked the most interest. Although at least five times larger than Earth, it is in the habitable zone, meaning it could potentially have liquid water on its surface depending on the composition of the atmosphere. Kapteyn b orbits its star once every 48 days.
Since Kapteyn’s Star is puts out much less energy than our sun, it could still be cool enough for liquid water despite being much closer to its star than Earth. The second planet, Kapteyn a, orbits every 121 days, making it too far away for water to be anything other than ice.
Kapteyn’s Star is thought to be a remnant of a dwarf galaxy that was absorbed into the Milky Way.Astronomers believe that the star and its planets have been around for 11.5 billion years, rouglhy 2.5 times as long as Earth.
“It does make you wonder what kind of life could have evolved on those planets over such a long time,” said Guillem Anglada-Escude, the lead author of the study.
The next step will be analyzing the atmosphere of the planet to determine if liquid water is in fact present. Although the technology to do this is still under development, Kapteyn b could be one of the first planets on the list for atmospheric analysis due to its close proximity to Earth.