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 | Moons – NASA Solar System Exploration
Of the terrestrial (rocky) planets of the inner solar system, neither Mercury nor Venus have any moons at all, Earth has one and Mars has its two small moons. In the outer solar system, the gas giants Jupiter …
In Depth | Asteroids – NASA Solar System Exploration
Stray asteroids and asteroid fragments have slammed into Earth and the other planets in the past, playing a major role in altering the geological history of the planets and in the evolution of life on Earth.
In Depth | Sun – NASA Solar System Exploration
The Sun orbits the center of the Milky Way, bringing with it the planets, asteroids, comets, and other objects in our solar system. Our solar system is moving with an average velocity of 450,000 miles …
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 | Kuiper Belt – NASA Solar System Exploration
According to one well-supported theory, the shifting orbits of the four giant planets (Jupiter, Saturn, Uranus, and Neptune) could have caused most of the original material -- likely 7 to 10 times the …
Asteroids, Comets & Meteors - NASA Solar System Exploration
Asteroids and comets – and the meteors that sometimes come from them – are leftovers from the formation of our solar system 4.6 billion years ago.
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.
In Depth | Ganymede – NASA Solar System Exploration
Over time, the orbits of most large satellites or planets tend to become circular, but that isn't the case for these three. Their resonance forces their orbits to become slightly elliptical, or eccentric.
In Depth | Phobos – NASA Solar System Exploration
It orbits Mars three times a day, and is so close to the planet's surface that in some locations on Mars it cannot always be seen. Phobos is nearing Mars at a rate of six feet (1.8 meters) every hundred …