Merrillville Community Planetarium
Bringing the Universe to the Merrillville Schools and Northwest Indiana

Closest Exoplanets

The closest star to our Sun is Proxima Centauri, at 4.2 light years away. It’s in the constellation Centaurus (the Centaur) viewed from the southern hemisphere. Two Earth-like planets have been found orbiting the red dwarf star.

Proxima b is roughly the size of Earth and is located in the middle of the “habitable zone” of Proxima Centauri. The habitable zone of a star is a band-like area where water can be in liquid form. Earth’s habitable zone includes Venus, Earth, and Mars.

Proxima c is about the mass of 6 Earths and is located farther away from the star’s habitable zone. This area is called the “snow line” where molecules like water, methane, and carbon dioxide freeze to become solids. Scientists are very curious about the formation of this planet and will study it further.

Proxima Centauri will probably be the first star to be visited in a future interstellar mission, like Breakthrough Starshot.