Scientists may have detected signs of a planet passing through stars outside the Milky Way, which could be the first planet to be found outside our galaxy.
NASA said at a news conference Monday that the possible exoplanet was discovered in a spiral galaxy by NASA's Chandra X-ray Observatory.
So far, all other exoplanets have been found in the Milky Way, most of them less than 3,000 light-years from Earth. This newly discovered possible exoplanet is about 28 million light-years away — thousands of times farther away than the Milky Way.
However, researchers will have to wait a long time to confirm whether they have discovered a Galactic exoplanet. Because of their large orbits, candidate planets won't pass through binary partners for the next 70 years, meaning it could take decades to confirm observations.
Nia Imara, an astrophysicist at the University of California, Santa Cruz, said in a statement: "We don't know when to look because of uncertainty about orbital running times. ”
If the planet really exists, experts say it must survive a supernova explosion that produces neutron stars or black holes. In the future, the companion star may also explode in the form of a supernova and explode the planet again at extremely high radiation levels.
The researchers will search the archives of Chandra and the European Space Agency satellite XMM Newton for more exoplanet candidates in other galaxies.