Astronomers May Have Located a Planet Outside of Our Galaxy for the First Time The possible planet was spotted in the Messier 51 galaxy, 28 million light-years away.
By Amanda Breen
The search for expolanets — those orbiting stars beyond our sun — is taking place outside of the Milky Way as we speak, and astronomers using NASA's Chandra X-ray Observatory have observed indicators of a planet in the Messier 51 (M51) galaxy, 28 million light-years away.
If confirmed, this planet, estimated to be the size of Saturn, would be the farthest from our own ever detected. Exoplanet candidates in the Milky Way galaxy are no more than 3,000 light-years from Earth.
The recent finding was made possible by transits, a phenomenon that occurs when a planet passes in front of a star and blocks some of the star's light, which leads to a dimming effect that can be picked up by telescopes. Thousands of exoplanets have been located with this method.
Researchers didn't think gas clouds or dust were responsible for the reduced brightness because such characterstics weren't present in the M51 event. The findings did support the presence of a plant, but that data still has to be confirmed.
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The planet is likely orbiting a neutron star or black hole at twice the distance of Saturn from the sun, which means that it could take approximately 70 years before scientists witness another transit. Additionally, the recent transition lasted only three hours — not allowing much time for verification.
But there's no guarantee conditions will even be the same at that point in the future. The "living" star could explode and cover the planet in radiation.
Although researchers have long held that planets populate galaxies outside of our own, confirming their existence would have major implications for future planetary searches, broadening the scope like never before.
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