Types of Exoplanet

Hot Jupiters

Mass: Up to 12 times

Jupiter’s mass

Size: 0.3 to 10.0 times

Jupiter’s radius

Number discovered: 1,458

Gas giants like Jupiter. The difference is these worlds orbit closer to their stars, with short orbits and blistering surface temperatures. WASP-76b is a planet so close to its host that it completes an orbit in under two days.

Sub-Neptunes

Mass: Up to 17 times Earth’s mass

Size: Over 2.0 times

Earth’s Radius

Number discovered: 1,719 Planets similar in size to the Solar System’s ice giant Neptune, they’re believed to be the most common type of planet in the Milky Way. Discovered in 2018, Kepler-1655 b has a radius around 2.3 times that of Earth, with five times our planet’s mass.

Super-Earths

Mass: Up to ten times Earth’s mass

Size: Between

0.8 and 4.0 times

Earth’s radius

Number discovered: 604 Rocky terrestrial worlds or gas planets more massive than Earth but smaller than Neptune. One example of a super-Earth is Gliese 15 A b, a rocky world 11 light years away which is over three times the size of Earth.

Terrestrial

Mass: Around that of Earth

Size: Between 0.5 to

2.0 times Earth’s radius

Number discovered: 186

These are small, rocky worlds like the Solar System’s inner planets Mercury, Venus, Earth and

Mars. TRAPPIST-1e is the fourth planet from its star, 40 light years from Earth. Existing in the habitable zone of its host, it could potentially have liquid water.