Astronomers believe that they may have found the first exoplanet outside our galaxy.
An exoplanet is a planet outside of our solar system that normally orbits a star other than our own sun in our galaxy.
The Saturn-sized planet has been identified in Whirlpool Galaxy which is 28m light years away.
The exoplanet appears to be orbiting an X-ray binary, made up of a normal star and a collapsed star or black hole.
Although nearly 5,000 exoplanets have been detected so far, all of them are in the Milky Way galaxy.
An exoplanet in the spiral Messier 51 (M51) galaxy – also called the Whirlpool Galaxy because of its distinctive shape – would be about 28m light years away.
The planet was found by the Center for Astrophysics at Harvard and Smithsonian in Cambridge, US. They found it using Nasa’s Chandra X-ray Observatory, by searching for a characteristic dip in the brightness of X-rays caused by the passage of a planet in front of the X-ray binary.