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.

Jan 9, 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.

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.

comets may exist in a huge cloud surrounding our solar system. 1951 — Astronomer Gerard Kuiper predicts the existence of a belt of icy objects just beyond the orbit of Neptune.

Defining the term planet is important, because such definitions reflect our understanding of the origins, architecture, and evolution of our solar system. Over historical time, objects categorized as planets have changed.

The first confirmed object from another star to visit our solar system, this interstellar interloper appears to be a rocky, cigar-shaped object with a somewhat reddish hue. The object, named ‘Oumuamua by its discoverers, is up to one-quarter mile (400 meters) long and highly-elongated—perhaps 10 times as long as it is wide.

The Kuiper Belt is a large region in the cold, outer reaches of our solar system beyond the orbit of Neptune. It's sometimes called the "third zone" of the solar system. Astronomers think there are millions of small, icy objects in this region – including hundreds of thousands that are larger than 60 miles (100 kilometers) wide.

May 18, 2020 · Astronomical units are a useful measure for distances in our solar system, while light years are more practical for distances to the stars. The nearest star system, Alpha Centauri, is seen from Saturn in this image from NASA’s Cassini spacecraft.

Dwarf planet Eris is a member of a group of objects that orbit in a disc-like zone beyond the orbit of Neptune called the Kuiper Belt. This distant realm is populated with thousands of miniature icy worlds, which formed early in the history of our solar system about 4.5 billion years ago.

Dwarf planet Pluto is a member of a group of objects that orbit in a disc-like zone beyond the orbit of Neptune called the Kuiper Belt. This distant realm is populated with thousands of miniature icy worlds, which formed early in the history of our solar system about 4.5 billion years ago.