Planet Compare – NASA Solar System Exploration
Oct 21, 2025 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
In Depth | Triton – NASA Solar System Exploration
Triton is named after the son of Poseidon (the Greek god comparable to the Roman Neptune). Until the discovery of the second moon Nereid in 1949, Triton was commonly known as simply "the satellite of …
In 1943, astronomer Kenneth Edgeworth hypothesized that many small, icy bodies exist in a disc in the region beyond Neptune, having condensed from widely spaced ancient material, and that from time …
In Depth | Kuiper Belt – NASA Solar System Exploration
As Uranus and Neptune drifted farther outward, they passed through the dense disk of small, icy bodies left over after the giant planets formed. Neptune's orbit was the farthest out, and its gravity bent the …
In Depth | Our Solar System – NASA Solar System Exploration
Our solar system consists of our star, the Sun, and everything bound to it by gravity – the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune; dwarf planets such as Pluto; …
In Depth | Proteus – NASA Solar System Exploration
Overview Proteus is one of the largest of Neptune's known moons, although it is not as big as Triton. The moon has an odd box-like shape and if it had just a little more mass it would be able to transform …
In Depth | Moons – NASA Solar System Exploration
In the outer solar system, the gas giants Jupiter and Saturn and the ice giants Uranus and Neptune have dozens of moons. As these planets grew in the early solar system, they were able to capture smaller …
Mars By the Numbers - NASA Solar System Exploration
Oct 21, 2025 · Mars is the fourth planet from the Sun, and the seventh largest. It’s the only planet we know of inhabited entirely by robots.
RPS 3D Viewer - NASA Solar System Exploration
Oct 21, 2025 · Moons About Moons BY DESTINATION Earth (1) Mars (2) Jupiter (95) Saturn (83) Uranus (27) Neptune (14) Pluto (5) Asteroids, Comets & Meteors About Asteroids, Comets & …
Pluto By the Numbers – NASA Solar System Exploration
Oct 21, 2025 · Pluto was once our solar system's ninth planet, but has been reclassified as a dwarf planet. It's located in the Kuiper Belt.