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.
Asteroids, Comets & Meteors - NASA Solar System Exploration
Our solar system’s small bodies – asteroids, comets, and meteors – pack big surprises. These chunks of rock, ice, and metal are leftovers from the formation of our solar system 4.6 billion years ago.
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 | Perseids – NASA Solar System Exploration
Meteors come from leftover comet particles and bits from broken asteroids. When comets come around the Sun, they leave a dusty trail behind them. Every year Earth passes through these debris trails, …
In Depth | Oumuamua – NASA Solar System Exploration
The first known interstellar object to visit our solar system, 1I/2017 U1 ‘Oumuamua, was discovered Oct. 19, 2017 by the University of Hawaii’s Pan-STARRS1 telescope, funded by NASA’s Near-Earth …
In Depth | Kuiper Belt – NASA Solar System Exploration
Researchers have found that some near-Earth asteroids are actually burned-out comets, and most of them would have started out in the Kuiper Belt. Many comets crash into the Sun or the planets.
In Depth | Moons – NASA Solar System Exploration
There are hundreds of moons in our solar system – even asteroids have been found to have small companion moons. Of the terrestrial (rocky) planets of the inner solar system, neither Mercury nor …
The Kuiper Belt should not be confused with the Oort Cloud, which is a thousand times more distant. In 1950, astronomer Jan Oort proposed that certain comets come from a vast, extremely distant …
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.