In an incredible world first, astrophysicists have detected multiple planets in another galaxy, ranging from masses as small as the Moon to ones as great as Jupiter. Given how difficult it is to find exoplanets even within our Milky Way galaxy, this is no mean feat. Researchers at the University of Oklahoma achieved this thanks to clever use of gravitational microlensing. The technique, first predicted by Einstein's theory of general relativity, has been used to find exoplanets within Milky Way, and it's the only known way of finding the smallest and most distant planets, thousands of light-years from Earth. As...