Microlensing detects invisible exoplanets

Gravitational microlensing is a clever technique that finds exoplanets by watching how their gravity bends light. When a star with a planet passes in front of a more distant star, the foreground system acts like a natural lens, temporarily brightening the background star's light. A subtle, short-lived spike in this light signals a planet's presence, allowing astronomers to infer its mass and orbit without direct imaging.