Life probably doesn’t exist on one of the most famous exoplanets, the gas giant Kepler-16b, which like Star Wars’ Tatooine orbits two stars. But a potential moon orbiting this planet might be a good place to search for ET.
Kepler-16b is a Saturn-sized planet 200 light-years away that orbits a pair of stars with about two-thirds and one-fifth the mass of the sun, respectively. It unfortunately has no surface to stand on, preventing any travelers from seeing the spectacular view of a double sunset.
But in a recent arxiv paper, astronomers posit that a hypothetical moon — which might be rocky like the moons of Jupiter and Saturn — could have the right temperature to host life. That’s because as the planet travels in its 229-day orbit around its dual parent stars, it would experience variation in the amount of light and heat it receives, essentially causing seasons. Changing seasons, in turn, can be responsible for weather patterns that stir up chemical reactions and are conducive to life.
The authors calculate that during the planet’s “summer,” it would receive approximately the same amount of sunlight as Mars, a planet with temperatures ranging between 68 and -124 degrees Fahrenheit. During its “winter” it would still be gathering more than six times the sunlight than Jupiter’s icy moon Europa, where the average surface temperature is -276 degrees Fahrenheit.
Though this might still seem rather cold to the majority of beings on Earth, scientists know that life can survive under extreme conditions. No Martian life has yet been found, but researchers still consider it a possibility. Europa is also thought to be a good place to search for life since it contains a large ocean of liquid water beneath its frozen crust.
Given these conditions, the authors wrote that “astrobiologists may have cause to take note” regarding the potential moons of Kepler-16b.