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; dozens of moons; and millions of asteroids, comets, and meteoroids.

The Sun is the largest object in our solar system. Its diameter is about 865,000 miles (1.4 million kilometers). Its gravity holds the solar system together, keeping everything from the biggest planets to the smallest bits of debris in orbit around it.

In the 400 years since Galileo's discovery, the rings have become Saturn’s telltale feature and are perhaps the most recognized characteristic of any world in our solar system. Cassini spent more than a decade examining them more closely than any spacecraft has before.

2025年1月9日 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.

2024年5月7日 · Jupiter is the fifth planet from the Sun, and the largest in the solar system – more than twice as massive as the other planets combined.

Jupiter is the fifth planet from our Sun and is, by far, the largest planet in the solar system – more than twice as massive as all the other planets combined. Jupiter's stripes and swirls are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium.

Mars is home to the largest volcano in the solar system, Olympus Mons. It's three times taller than Earth's Mt. Everest with a base the size of the state of New Mexico.

2025年1月9日 · The Jovian moon Io is likely the most geologically active body in the solar system, offering insight into tidal heating, volcanic processes, and other phenomena. However, its location within Jupiter''s radiation belt presents significant engineering challenges that must be addressed to enable future missions to Io.

2025年1月9日 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.

Cassini carried a passenger to the Saturn system, the European Huygens probe—the first human-made object to land on a world in the distant outer solar system. After 20 years in space — 13 of those years exploring Saturn — Cassini exhausted its fuel supply.