This list contains the closest currently known terrestrial extrasolar worlds, orbiting within 50 light years of the Solar System.
They may be composed primarily of silicate rocks and/or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun.
The closest extrasolar planets overall to Earth are Proxima Centauri b, c, and d, each located 4.22 light years away. Proxima b is the closest potentially habitable planet to Earth.
Terrestrial extrasolar planets discovered (incomplete)[]
A note should be made that this list is almost certainly not all of the terrestrial worlds near our Solar System, but simply a list of the closest ones that have been proven to exist. The list contains 37 extrasolar planets, 11 of which likely lie in the "habitable zone" of their stars.
There are roughly 2,000 stars at a distance of up to 50 light-years from the Solar System, with 64 of them being G-type stars, like the Sun. As many as 15% of these could contain an Earth-sized planet in the habitable zone.
On November 4, 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of sun-like stars and red dwarf stars within the Milky Way Galaxy. 11 billion of these estimated planets may be orbiting sun-like stars. The nearest such planet may be as close as 12 light-years away.
On August 24, 2016, astronomers announced the discovery of a rocky planet in the habitable zone of Proxima Centauri, the closest star to Earth. Named Proxima b, the planet is 1.3 times the mass of Earth and has an orbital period of roughly 11.2 Earth days. Another likely candidate is Alpha Centauri, Earth's nearest Sun-like star system, located 4.37 light years away. Estimates place the probability of finding a habitable planet around Alpha Centauri A or B at roughly 85%. Alpha Centauri is the target of several exoplanet-finding missions, including Breakthrough Starshot and Mission Centaur, the latter of which is chronicled in the 2016 documentary film, "The Search for Earth Proxima."
Notes:
- M⊕ = Earth mass
- R⊕ = Earth radii
Note: There is no scientific consensus about terrestrial composition of most of the planets in the list.
Another note to add is that atmospheric compositions and atmospheric pressures of most extrasolar planets are not known. The surface temperatures are estimated based on computer models and expert opinions, but the surface temperatures could be completely different based on other factors.
Statistics[]
Distance | Lying within the habitable zone | All |
---|---|---|
< 10 light-years | 1 | 2 systems |
< 20 light-years | 6 | 15 |
< 30 light-years | 8 | 22 |
< 40 light-years | 10 | 24 |
< 50 light-years | 11 | 31 |