Vesta
Key facts
- What it is
- Large main-belt asteroid
- Size
- About 525 km across
- Discovered
- 1807, by Heinrich Olbers
- Spacecraft
- Dawn (in orbit 2011–2012)
- Orbit group
- Main-belt Asteroid
- Average distance from the Sun
- 2.36 au (about 350 million km)
- Time to go round the Sun
- 3.6 years
- Closest and farthest from the Sun
- 2.15 to 2.57 au
- Tilt of its orbit
- 7.1°
- Spins once every
- 5.3 hours
An au (astronomical unit) is Earth's average distance from the Sun, about 150 million km. Orbit figures are from open tracking data, figures last updated 1 Nov 2026.
The howardites, the meteorites this site is named after, come from Vesta. Together with the eucrites and diogenites they form the HED meteorites, pieces of Vesta's crust and deeper rock, so a howardite in your hand is very probably a fragment of this world.
Heinrich Olbers discovered Vesta in 1807. At about 525 kilometres across it is the second most massive body in the asteroid belt, and it is the brightest asteroid in our sky. On rare occasions it can just be seen without a telescope from a very dark site.
Vesta is special because it melted early in its history and separated into layers: an iron core, a rocky mantle and a basalt crust, much like a small version of Earth. Most asteroids never did this. Eucrites are basalts from its crust, diogenites come from deeper down, and howardites are rubble of both mixed together by impacts on the surface.
NASA's Dawn spacecraft orbited Vesta from 2011 to 2012. It mapped a vast impact basin near the south pole, named Rheasilvia, about 500 kilometres wide, almost as broad as Vesta itself, with a central peak rising some 20 kilometres. The blow that made it threw enormous amounts of rock into space. Many small asteroids, called vestoids, share Vesta's orbit and colour, and some of them slowly drift onto paths that cross Earth's. That is how pieces of Vesta reach us as meteorites.
Dawn's measurements of Vesta's surface chemistry matched the HED meteorites closely, confirming a link that scientists had suspected for decades from the colour of its reflected light.