
A rare meteorite showered hundreds of fragments over Turkey in 2015 – and we may now know the exact location in the solar system it came from.
Peter Jenniskens at NASA’s Ames Research Center and colleagues have traced the meteorite to a crater on the asteroid Vesta, one of the largest objects in the asteroid belt.
They believe the meteorite – an estimated one metre in diameter – arose from an impact to Vesta approximately 22 million years ago, launching debris into space and resulting in the 17 kilometre-wide Antonia impact crater (pictured above).
Advertisement
NASA’s Dawn spacecraft visited Vesta in 2011, mapping out the asteroid’s surface. Several clues point to Vesta as being the source of the meteorite, says Jenniskens.
The meteorite was captured by hundreds of security cameras as it fell over the Turkish village of Sariçiçek. By studying video footage of the fireball in the sky, the team calculated the trajectory of the meteorite as it approached Earth.
They discovered that the object had a short orbit, suggesting it had originated from the inner asteroid belt – which is where Vesta is found.
Both the size of the Antonia impact crater and the age of the material around it suggest it is the likely origin for the Sariçiçek meteorite, says Jenniskens.
Objects are exposed to high-energy radiation called cosmic rays as they travel through space, producing noble gases and isotopes. By studying these substances in the meteorite, the team were able to determine that it had travelled through space for 22 million years.
The meteorite was the first of a type called howardite to ever impact Earth and be filmed in the act. Howardite belongs to a group classified as howardite-eucrite-diogenites (HED), which astrophysicists have long suspected originated from Vesta or asteroids associated with it.
“About one-third of all HED meteorites are 22 million years old,” says Jenniskens. “What it says is that this particular rock came from a big collision event, so we were looking for a big crater.”
Meteoritics & Planetary Science
Article amended on 12 April 2019
We clarified the sense in which this meteorite was a first