It's a bit boggling that they plan to find "rogue" planets by "microlensing"[2]. To quote from [1] > The mission will stare at the a dense star region toward t

It's a bit boggling that they plan to find "rogue" planets by "microlensing"[2]. To quote from [1] > The mission will stare at the a dense star region toward the direction of the center of our Milky Way galaxy to observe microlensing events. So you have a series of images of a field full of thousands (tens of thousands?) of stars, and you ("you" meaning "a great honking bunch of computer logic") compare one image to the next looking for _one_ of the stars to have briefly doubled, or turned into a little ring. And then you derive a lot of info from that brief distortion event. [1] https://roman.gsfc.nasa.gov/faq.html https://roman.gsfc.nasa.gov/faq.html [2] https://en.wikipedia.org/wiki/Gravitational_microlensing https://en.wikipedia.org/wiki/Gravitational_microlensing