Our Milky Way galaxy is home to billions of planets orbiting billions of stars in billions of planetary systems. But lurking in the spaces between, not bound to any star, are free-floating worlds. Astronomers refer to these as “rogue planets” because they were kicked out of their planetary systems.
Astronomers have already started to find handfuls of these lonely worlds, but the planets remain mysterious. Two space telescopes set to launch in the 2020s may change that, according to a recent paper published in The Astrophysical Journal Letters.
Rogue planets are hard to study because they’re on their own. When a planet is orbiting a star, astronomers can watch the star to learn more about the planet. For example, when a planet passes in front of its star from Earth’s point of view, astronomers can use information about how much of the star’s light is eclipsed to deduce how large ...
