Kepler 186f earthlike concept

Kepler-186f is the first Earth-sized exoplanet discovered in the habitable zone of a red dwarf star, located 500 light-years away.

About this subject

Kepler-186f was discovered in 2014 by NASA's Kepler space telescope, marking a milestone in the search for potentially habitable planets. It orbits the red dwarf star Kepler-186 in the constellation Cygnus, about 500 light-years from Earth. The planet has a radius only 10% larger than Earth's, classifying it as a rocky world, though its exact mass and composition remain unknown. Its orbit takes about 130 Earth days, placing it within the optimistic habitable zone of its star, where liquid water could exist on the surface.

Kepler-186 is an M1V-type red dwarf with a surface temperature around 4,000 K, much cooler than the Sun. Therefore, its habitable zone is much closer to the star than the Solar System's. Kepler-186f receives about one-third of the energy Earth receives from the Sun, positioning it near the outer edge of the habitable zone. If it has an Earth-like atmosphere, it would likely be a cold world with subzero average temperatures, but life could still be possible with sufficient greenhouse warming.

Interestingly, the Kepler-186 system hosts four other confirmed planets (Kepler-186b, c, d, e), all closer to the star and too hot for liquid water. Kepler-186f is the fifth and farthest. The discovery was published in the journal Science in April 2014, generating great excitement as the first Earth-sized planet confirmed in a habitable zone. Since then, many more have been found, but Kepler-186f remains a key target for studies of habitability around red dwarfs.

Frequently Asked Questions

How far is Kepler-186f from Earth?

Kepler-186f is about 500 light-years away, in the constellation Cygnus.

Is Kepler-186f truly habitable?

It lies in the habitable zone, but habitability depends on factors like atmosphere and composition. It is known to be rocky and Earth-sized, but its surface temperature and conditions are unknown.

How many planets are in the Kepler-186 system?

Five planets have been confirmed (b, c, d, e, f). Kepler-186f is the outermost and the only one in the habitable zone.