Gravitational Microlensing

Gravitational microlensing is an observational technique that exploits Einstein's prediction that massive objects bend light. When a star or planet passes in front of a distant star from our perspective, its gravity acts as a lens, magnifying and distorting the background star's light. First proposed by Bohdan Paczynski in 1986, this method has discovered hundreds of exoplanets and provides unique sensitivity to low-mass planets and dark matter.