what is kepler 186f

Kepler-186f is an exoplanet, meaning it orbits a star outside our solar system. It is especially notable because it was the first Earth-sized planet found in the habitable zone of another star, where liquid water might potentially exist on the surface.

Quick Scoop

• It orbits the red dwarf star Kepler-186 in the constellation Cygnus.

• It was announced in 2014 from data collected by NASA’s Kepler space telescope.

• Its size is just a little larger than Earth, with a radius about 1.11 times Earth’s.

• Scientists do not yet know its mass, atmosphere, or whether it actually has water.

• It is about 500 to 580 light-years from Earth, depending on the source cited.

Why it matters

Kepler-186f became famous because it showed that Earth-size planets can exist in habitable zones around other stars. That made it an important milestone in the search for potentially life-friendly worlds.

Important caveat

“Habitable zone” does not mean habitable for sure. It only means the planet is at a distance where liquid water might exist under the right conditions, and Kepler-186f’s real surface conditions are still unknown.

TL;DR: Kepler-186f is a small, likely rocky exoplanet that orbits in the habitable zone of a red dwarf star, and it became famous because it was the first Earth-sized planet found there.