Astronomers believe five binary-star systems identified by NASA’s now-defunct Kepler Space Telescope could have the right properties to support extraterrestrial life, according to new calculations.
"Life is far most likely to evolve on planets located within their system's habitable zone, just like Earth,” said Nikolaos Georgakarakos, first author of a paper on the planets, and a research associate at New York University Abu Dhabi.
“Here we investigate whether a habitable zone exists within nine known systems with two or more stars orbited by giant planets. We show for the first time that Kepler-34, -35, -64, -413 and especially Kepler-38 are suitable for hosting Earth-like worlds with oceans."
"We believe that our method can be used as a diagnostic tool to quickly assess whether a system is likely to host a habitable planet. Then [astronomers] can point our telescopes towards the best candidate systems,” he told The Register.
Binary stars are common; it’s estimated more than half of the stellar systems in space are made up of twin suns. The chance of these systems hosting exoplanets that may be habitable, however, is believed to be lower than ones with lone stars, like our own Solar System. Only giant exoplanets – at least the size of Neptune – have been found around these configurations with multiple suns so far, and they’re typically bad news for life.
The gravitational interactions between the numerous stars and the giant planets are more likely to provide an unstable environment for smaller, rocky planets – that could be potentially habitable – to survive. Giant planets could kick them away to the distant corners of the system away from their host stars’ habitable zones.
Brit uni's AI algorithm clocks 50 exoplanets hidden in Kepler space 'scope archivesREAD MORE
But star systems Kepler-34, -35, -38, -64 and -413 seem to buck the trend, according to a study published in the Frontiers in Astronomy and Space Sciences Journal. These far-flung systems, located between 2,764 and 5,933 light-years from Earth in the constellations Lyra and Cygnus, could bathe their exoplanets with enough sunshine and warmth that liquid water could exist on their planetary surfaces, despite them being neighbors with turbulent giant bodies.
"We've known for a while that binary star systems without giant planets have the potential to harbor habitable worlds,” Ian Dobbs-Dixon, co-author on the paper and an associate professor of physics at New York University Abu Dhabi in the United Arab Emirates, said in a statement. “What we have shown here is that in a large fraction of those systems Earth-like planets can remain habitable even in the presence of giant planets."
The team predicted the size of each system’s habitable zone by looking at the stars’ mass, luminosity, and energy, as well as their accompanying giant planets’ orbits. The larger the zone, the more likely it could support life on smaller exoplanets.
But before you get too excited about the idea of a habitable Tatooine-like planet, a world that orbits twin stars in the fictional Star Wars universe, the team’s results are purely speculative at the moment. It depends on whether there are real Earth-like planets that do lie in these system’s habitable zones; none have been found yet so far because they’re more difficult to detect.
“Our best candidate for hosting a world that is potentially habitable is the binary system Kepler-38, approximately 3970 light years from Earth, and known to contain a Neptune-sized planet," Georgakarakos added. "Our study confirms that even binary star systems with giant planets are hot targets in the search for Earth 2.0. Watch out Tatooine, we are coming!" ®