The project monitors the brightness of thousands of red dwarf stars with the goal of finding transiting planets.
As red dwarf stars are small, any transiting planet blocks a larger proportion of starlight than transits around a Sun-like star would, allowing smaller planets to be detected through ground-based observations.
[3] The original MEarth-North[4] observatory on Mount Hopkins consists of eight RC Optical Systems 40 cm (16 in) f/9 Ritchey-Chrétien telescopes equipped with 2048 × 2048 Apogee U42 CCDs, infrared filters, and equatorial mounts.
[3] In 2014, the MEarth-South observatory began operations[6] from the Cerro Tololo Inter-American Observatory site east of La Serena, Chile, extending MEarth's coverage to the southern celestial hemisphere using a nearly-identical eight-telescope array.
[4] Unlike MEarth-North, the telescopes in Chile are also sensitive to red light.