Rogue planets wander through space without orbiting a star, and now scientists have found two more of these free-floating worlds.
For centuries, the very existence of rogue planets was hypothetical. Because they’re not close to a star that lights them up, they’re tremendously difficult to spot. Then a technique known as gravitational microlensing came around.
Using gravitational microlensing, scientists find planets by noting when a rogue planet interrupts a star’s light from our point of view. The planet suddenly acts as a lens for the star’s light, curving it as it would be seen from Earth. The bigger the planet, the bigger the interruption.
Read more at Popular Mechanics