Exoplanet
A planet that orbits a star other than our Sun. Over 5,500 confirmed as of 2025, with thousands more candidates awaiting verification.
An exoplanet (or extrasolar planet) is a planet outside our solar system, orbiting a star other than the Sun. The first confirmed exoplanet around a Sun-like star was discovered in 1995; today, over 5,500 are confirmed.
Most exoplanets are detected indirectly using methods such as the transit method (watching for tiny dips in starlight as a planet passes in front of its star) and the radial velocity method (measuring the gravitational tug a planet exerts on its star). Direct imaging is possible only for a few large, bright exoplanets far from their host stars.
The James Webb Space Telescope can analyse exoplanet atmospheres in detail, searching for biosignatures — chemical fingerprints of possible life. Several Earth-sized planets have been found in the habitable zones of their stars.