In Depth | Moons – NASA Solar System Exploration
Moons – also called natural satellites – come in many shapes, sizes and types. They are generally solid bodies, and few have atmospheres. Most planetary moons probably formed out the discs of gas and …
Planet Compare - NASA Solar System Exploration
Apr 9, 2026 · 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 | 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 | Phobos – NASA Solar System Exploration
Phobos is the larger of Mars' two moons and is 17 x 14 x 11 miles (27 by 22 by 18 kilometers) in diameter. It orbits Mars three times a day, and is so close to the planet's surface that in some …
In Depth | Titan – NASA Solar System Exploration
Saturn's largest moon, Titan, is an icy world whose surface is completely obscured by a golden hazy atmosphere. Titan is the second largest moon in our solar system. Only Jupiter's moon Ganymede is …
In Depth | Uranus Moons – NASA Solar System Exploration
Centuries later, the moons of Uranus pay homage to the famous playwright. While most satellites orbiting other planets take their names from ancient mythologies, Uranus' moons are unique in being …
In Depth | Sun – NASA Solar System Exploration
Moons As a star, the Sun doesn’t have any moons, but the planets and their moons orbit the Sun. Rings The Sun would have been surrounded by a disk of gas and dust early in its history when the solar …
In Depth | Earth's Moon – NASA Solar System Exploration
Earth's Moon is the only place beyond Earth where humans have set foot, so far. Earth's only natural satellite is simply called "the Moon" because people didn't know other moons existed until Galileo …
In Depth | Saturn Moons – NASA Solar System Exploration
The Voyager and Pioneer flybys of the 1970s and 1980s provided rough sketches of Saturn’s moons. But during its many years in Saturn orbit, NASA’s Cassini spacecraft discovered previously unknown …
The Sun By the Numbers - NASA Solar System Exploration
Apr 9, 2026 · The Sun is the star at the heart of our solar system. Its gravity holds the solar system together, keeping everything – from the biggest planets to the smallest bits of debris – in its orbit.