
A rocky exoplanet with a mass higher than Earth's but substantially lower than ice giants.A super-Earth is a rocky exoplanet with a mass between that of Earth and the ice giants like Uranus or Neptune, typically ranging from about 1.5 to 10 Earth masses. These planets are common in the galaxy, often found in close orbits around their host stars, and they challenge our understanding of planetary formation and habitability. Super-Earths can have a wide variety of interiors, from iron-rich cores with thin mantles to water worlds with deep global oceans, depending on their formation history and distance from their star.
The first super-Earth was discovered in 1992 around a pulsar, but the term gained wide usage after the 2005 discovery of Gliese 876d. The Kepler mission, launched in 2009, revealed that super-Earths are among the most common planet types in the Milky Way.
Super-Earths form in the protoplanetary disk around a young star, accumulating material through collisions and gravitational attraction. Their larger mass means stronger gravity, which compresses their interiors more than Earth's, leading to denser cores and potentially thicker atmospheres. The boundary between super-Earths and mini-Neptunes is thought to be set by atmospheric loss: planets below a certain mass lose their primordial hydrogen envelopes, leaving bare rocky surfaces, while more massive ones retain thick gaseous atmospheres.
Super-Earths are prime targets in the search for habitable exoplanets, as some may have conditions suitable for liquid water, and they are studied to refine models of planetary formation and evolution.
Some super-Earths are so dense that they are thought to be made largely of diamond, formed from carbon-rich parent stars.

























