Asteroids

Overview

Asteroids, sometimes called minor planets, are rocky, airless remnants left over from the early formation of our solar system about 4.6 billion years ago.

Most asteroids can be found orbiting the Sun between Mars and Jupiter within the main asteroid belt. Asteroids range in size from Vesta – the largest at about 329 miles (530 kilometers) in diameter – to bodies that are less than 33 feet (10 meters) across. The total mass of all the asteroids combined is less than that of Earth's Moon.

Latest Count
For the most up to date count of asteroids in our solar system, please visit NASA/JPL's Solar System Dynamics website.

planetary defense

NASA to Track Asteroid 2024 PT5 on Next Close Pass, January 2025

Because 2024 PT5 has a similar motion to Earth’s around the Sun, the asteroid will linger as a distant companion of our planet for a few months at a distance of about nine times farther away from Earth than the Moon. During this time, the object will never be captured by Earth’s gravity. So while it’s not quite a “mini-moon,” 2024 PT5 is an interesting object and NASA has plans to track it with planetary radar.

Learn More

An artist's concept of an asteroid.

Featured Asteroids

NASA has sent several robotic spacecraft to encounter asteroids up close to learn more about their composition and size.

Psyche

Bennu

A grainy image with a distant asteroid circled

Apophis

An image of asteroid Dinkinesh, a pair of grey asteroids with a slightly jagged surface, taken from the Lucy spacecraft.

Dinkinesh and Selam

Didymos and Dimorphos

Vesta

Eros

Ida and Dactyl

Itokawa

Planetary Defense Coordination Office (PDCO)
The PDCO manages NASA's mission to find, track, and better understand asteroids and comets that could pose an impact hazard to Earth.
Center for Near Earth Object Studies (CNEOS)
CNEOS computes high-precision orbits for Near-Earth Objects (NEOs) in support of NASA’s Planetary Defense Coordination Office.
Minor Planet Center
An alphabetical list of asteroid names.
National Space Science Data Center: Asteroids
Asteroid fact sheets, and more.