Astronomers have found hints of what could be the first planet ever to be discovered outside the galaxy. The possible Saturn-sized planet discovered by Nasa's Chandra X-Ray Telescope is in which of the following galaxies?

Astronomers have found hints of what could be the first planet ever to be discovered outside the galaxy. The possible Saturn-sized planet discovered by Nasa's Chandra X-Ray Telescope is in which of the following galaxies? Correct Answer Messier 51

The correct answer is Messier 51​.

Key Points

• Astronomers have found hints of what could be the first planet ever to be discovered outside the galaxy.
• The possible Saturn-sized planet discovered by Nasa's Chandra X-Ray Telescope is in the Messier 51 galaxy.
• This is located some 28 million light-years away from the Milky Way.
• Nearly 5,000 "exoplanets" - worlds orbiting stars beyond our Sun - have been found so far.

Important Points

• ​The potential exoplanet is named M51-ULS-1b.
• The Messier 51 (M51) galaxy is also known as the Whirlpool galaxy.
• For this study, astronomers used Nasa's Chandra X-ray Observatory and the European Space Agency's XMM-Newton space telescope to look at three galaxies beyond the Milky Way.
• In total, they looked at 55 different systems in M-51, the Whirlpool galaxy, 64 systems in Messier 101 (M-101), or the "Pinwheel galaxy," and 119 systems in Messier 104, or the “Sombrero galaxy".

Additional Information

•  The first exoplanet discovered was in 1992 and, since then, most exoplanets found have been less than 3,000 light-years from Earth.