A 3rd planet, just 1.5 times the size of Earth, may also be orbiting the star. ... The bottom graphic shows the relative sizes of the Kepler-18 and its known planets to the Sun and Earth.

This video starts with the Moon, runs through our solar system’s rocky and gas planets, and then takes us from our regular-sized Sun to the biggest hypergiant star, all to a pulse-pounding beat ...

These planets are about the size of Earth, and fall in the so-called “Goldilocks zone” of habitability, making them candidates to contain life.

It's not always easy to imagine just how big the other planets are. Here, a space artist's thought experiment turns into a lesson in Earth's relative size.

The map, entitled "Surface Area" on Munroe's site xkcd.com, is a wonderful visualization of the relative sizes of all the major solid bodies in the solar system presented as a familiar world map.

In a groundbreaking discovery, astronomers have identified TOI-1846 b, a super-Earth exoplanet located 154 light-years away.

In this artist’s conception, the sizes of the planets relative to the star have been exaggerated. Kepler-138 b, in the foreground, is likely an airless rocky world.