 So far, we've found nearly 4,000 exoplanets in our own galaxy. But are there planets in other galaxies outside of ours? It's a trope of science fiction, and as of a few days ago, it's a fact of a scientific paper. And this is your space pod for Thursday, February 15th, 2018. Einstein's theory of general relativity, a hotbed of scientific activity over the past couple years, finally comes back into play to help us find extragalactic exoplanets. A study at the University of Oklahoma by postdoctoral student Zinu Dai and professor Eduardo Geras used a technique known to astrophysicists and cosmologists as gravitational microlensing. This technique looks at the light from a distant object as it is bent and focused by a closer object, but specifically without needing electromagnetic radiation or light of any kind from the lensing object in the foreground. Now this allows for us to take precise measurements of small mass objects from very, very far away. In addition, the transit method of exoplanet detection was utilized, looking for the dips in the amount of light coming from a star as an exoplanet crosses its disk. Now the galaxy being observed here, very aptly named RXJ1131-1231, has a supermassive black hole at its core and the microlensing properties of the supermassive black hole enable this observation to occur. Additional data was gathered from the Chandra X-ray telescope and some serious crunching by a supercomputer at the University of Oklahoma showed the presence of exoplanets, roughly the mass of Jupiter to that of Earth's moon to the tune of nearly 2,000 unbound per main sequence star. Yes, 2,000 exoplanets per main sequence star. Now this technique for observation is now available to astronomy as a whole, so telescopes such as the European Southern Observatory's very large telescope, its upcoming extremely large telescope and even NASA's James Webb Space Telescope, can perform similar studies. Now don't forget to check out last week's show Orbit 11.06 where we talk about the epic Falcon Heavy test flight and what that means for the future of spaceflight and if you'd like to tune in at 1,800 coordinated universal time every Saturday to watch our live shows. So until the next space pod, keep exploring.