Astronomers Spot Signs of Planets Outside the Milky Way

Scientists have confirmed the existence of over 3,600 exoplanets—planets outside our solar system—and that number’s steadily increasing. But all of those planets reside within our own Milky Way galaxy. Tiny and dim in comparison to stars, planets beyond our galaxy’s boundaries are extremely difficult to spot. But as Elaina Zachos at National Geographic reports, astronomers have used a technique known as microlensing to detect signals from a galaxy 3.8 billion light years away that seem to suggest it is chock full of planets, ranging in size from our moon to Jupiter.

According to a press release, astronomer Xinyu Dai and postdoctoral researcher Eduardo Guerras used data from NASA’s Chandra X-ray Observatory to conduct their study. Gravitational microlensing is not a new concept; it was predicted by Einstein and confirmed in 1979. The idea is that massive objects can warp space-time so much that the light from an object behind it is also warped, appearing to curve around the closer “lens.” This effect distorts or magnifies the light of the distant object, making it visible when it otherwise would be lost in the night sky. For example, lensing recently helped researchers spot the distant galaxy SPT0615-JD, which lies 13.3 billion light years away.

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(University of Oklahoma)

Researchers estimate more than a trillion planets could exist in the elliptical galaxy at the center of this image.

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This is the first time anyone has discovered planets outside our galaxy. 'These small planets are the best candidate for the signature we observed in this study using the microlensing technique.‘We analyzed the high frequency of the signature by modelling the data to determine the mass.

 

Astronomers have directly measured the spin of a supermassive black hole in a quasar that is located 6 billion light years away.