2008 TC3
Key facts
- What it is
- Small asteroid that struck Earth on 7 October 2008
- Size
- About 4 m across
- Discovered
- 2008, by the Catalina Sky Survey
- Spacecraft
- Fell over Sudan; meteorites recovered
- Orbit group
- Apollo
- Average distance from the Sun
- 1.31 au (about 200 million km)
- Time to go round the Sun
- 547 days
- Closest and farthest from the Sun
- 0.9 to 1.72 au
- Tilt of its orbit
- 2.5°
- Closest its orbit comes to Earth's
- 1,200 km (0 times the Moon's distance)
- Spins once every
- 1.6 minutes
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.
2008 TC3 was the first asteroid ever found in space before it hit the Earth. Richard Kowalski spotted it on 6 October 2008 with a survey telescope on Mount Lemmon in Arizona. Within hours, calculations showed that it would enter the atmosphere over northern Sudan about 19 hours after its discovery.
It was small, about 4 metres across, and posed no danger. Astronomers around the world raced to observe it, measuring its colour and the way its brightness flickered as it tumbled. On 7 October, at 02:46 universal time, it struck the atmosphere exactly as predicted and exploded at a height of about 37 kilometres over the Nubian Desert. A passing airliner's crew saw the flash, and a weather satellite recorded the fireball.
Two months later the astronomer Peter Jenniskens and Muawia Shaddad of the University of Khartoum led a search with students and staff, walking in long lines across the desert. They found the first fragment within hours. Over several expeditions, around 600 pieces were collected, together weighing about 10.5 kilograms. The meteorite was named Almahata Sitta, Arabic for Station Six, after a railway station on the line nearby.
Most of the fragments are ureilites, a rare kind of carbon-rich achondrite, but the search also turned up pieces of many other meteorite types, including several kinds of chondrite. 2008 TC3 seems to have been a mixed rubble pile of rocks from different sources, something no one had expected.
It was the first time a meteorite could be studied alongside telescope observations of the very asteroid it came from.