The search beyond our own galaxy never fails to keep uncovering new and exciting things about our mysterious universe. One of the most recent potential discoveries is a planet in the Messier 51 (M51) or Whirlpool galaxy. What makes this planet, named M51-ULS-1b, so special is the fact it transmits a star, just like our planet revolves around the Sun. These are termed exoplanets, and before last week, no exoplanets outside our Milky Way had been discovered.

Astronomers use the European Space Agency’s XMM-Newton space telescope and NASA’s Chandra X-ray Observatory to search for these types of planets beyond the Milky Way. Sifting through 55 different galaxies, the team spotted the special planet due to the fact it briefly blocked light and X-ray emissions whilst transitioning in front of the star. These techniques have been utilized to pick up planets to 3,000 light-years all over our galaxy. Though M51 is 28 million light-years away, quite a distance further!

Using the data collected from the X-ray Observatory, the planet has been estimated to be around the size of Saturn and be positioned around twice as far as the ringed giant is from the Sun.

This discovery has the potential to trigger a new era of planet detection and study, allowing more puzzle pieces of the universe to come together. Although M51-ULS-1b will not orbit around its star again for another 70 years, so we have to wait a long time to double check if these results truly are correct. Co-author Julia Berndtsson added a statement about this issue “We know we are making an exciting and bold claim so we expect that other astronomers will look at it very carefully … We think we have a strong argument, and this process is how science works.”

Source study: Nature Astronomy – A possible planet candidate in an external galaxy detected through X-ray transit