IANA astronomer, but I believe that the typical method of planet detection relies on the assumption that planets revolve around stars. They can detect planets

IANA astronomer, but I believe that the typical method of planet detection relies on the assumption that planets revolve around stars. They can detect planets by measuring the tiny wobble of stars caused by the gravity of revolving planets. So I was wondering how the hell they detect free-floating (orphan) planets. The article explains that they use gravitational microlensing, which is a pretty cool technique. http://en.wikipedia.org/wiki/Gravitational_microlensing http://en.wikipedia.org/wiki/Gravitational_microlensing From the article: > A 5.9-foot (1.8-meter) telescope at Mount John University Observatory in New Zealand is used to regularly scan the copious stars at the center of our galaxy for gravitational microlensing events. These occur when something, such as a star or planet, passes in front of another, more distant star. The passing body's gravity warps the light of the background star, causing it to magnify and brighten. Heftier passing bodies, like massive stars, will warp the light of the background star to a greater extent, resulting in brightening events that can last weeks. Small planet-size bodies will cause less of a distortion, and brighten a star for only a few days or less.