Planet beyond Milky Way

  • Using data from NASA's Chandra X-ray Observatory astronomers have spotted signs of a planet in a star system outside the Milky Way, which, if it's confirmed, would be the first ever found in another galaxy.
  • The possible planet was discovered in a spiral galaxy called Messier 51, also known as the Whirlpool Galaxy, more than 23 million light-years from Earth.
  • The first exoplanets, or planets outside the solar system, were discovered in the 1990s, and they required combining a number of complicated detection techniques. Since then, however, NASA missions like the Kepler Space Telescope and the Transiting Exoplanet Survey Satellite (TESS) have uncovered a bonanza of worlds throughout the galaxy.
  • Typically, astronomers use what's known as the "transit method" to look for planets. Transits occur when a planet orbits in front of its parent star, temporarily blocking part of it and causing an observable dip in the star's light.