A team of Polish astronomers has spotted a so-called orphan planet, or a rogue planet, which wanders lonely along the Milky Way. Object OGLE-2016-BLG-1928 was found using microlensing.
Microlensing is a technique that allows you to observe how a dim and usually invisible celestial body distorts the light from another object, for example, a star that is nearby.
This time, astronomers paid attention to the light of a star in the Sagittarius constellation. They recorded the shortest microlensing event that lasted 41.5 minutes. It happened back in 2016. All these years, scientists have been observing the object. Finally, they confirmed that this event was caused by the smallest orphan planet known to science. It is similar in size to Earth or Mars.
Previously, all rogue planets found were several times heavier than Jupiter, whose mass is 318 times that of Earth. It is not yet clear how objects the size of our planet end up in interstellar space.
Scientists estimate billions of rogue, free-floating planets to exist in our Galaxy, but only a bunch of candidates have been detected among nearly 4,000 worlds beyond our Solar System.