Most of the exoplanets we’ve discovered have been in relatively tight orbits around their host stars, allowing us to track them as they repeatedly loop around them. But we’ve also discovered a handful of planets through a phenomenon that’s called microlensing. This occurs when a planet passes between the line of sight between Earth and another star, creating a gravitational lens that distorts the star, causing it to briefly brighten.
The key thing about microlensing compared to other methods of finding planets is that the lensing planet can be nearly anywhere on the line between the star and Earth. So, in many cases, these events are driven by what
→ Continue reading at Ars Technica