As our ability to study space has improved, our definitions of planets have evolved.

Comets are ancient relics from the Solar System's formation that may have delivered water and the building blocks of life to early Earth.

The Vera C. Rubin Observatory has a great view of the Cosmos — and of the Earth below.

The giant planets of our Solar System all have rings, as do some dwarf planets and even asteroids. So why don’t Mercury, Venus, Earth, or Mars?

A planetary nebula teaches us about how stars die, and a new Artemis architecture changes our plans for Mars.

Chang’e‑7 is China’s mission to seek out water ice on the Moon.