Carancas
Key facts
- Country
- Peru
- Diameter
- 13.5 m
- Age
- formed on 15 September 2007
- Location
- 16.66° S, 69.04° W
A small crater about 13.5 m across on the high Altiplano near Lake Titicaca, which quickly filled with groundwater after the impact.
On 15 September 2007 a fireball streaked across the sky over the Altiplano, the high plateau of southern Peru, near Lake Titicaca. Moments later a stony meteorite slammed into the ground near the village of Carancas, about 3,800 m above sea level, blasting out a crater about 13.5 m across. It was a rare and surprising event that challenged scientists' ideas about small stony meteorites.
The impact. Local people heard a loud explosion and saw a cloud of dust and smoke. When they reached the site, they found a fresh crater with a raised rim, and water quickly seeped in to fill it, because groundwater lies close to the surface there. Fragments of the meteorite were found in and around the crater.
A surprise for scientists. Carancas was a stony meteorite, an ordinary chondrite of type H4–5, the most common kind of meteorite. Small stony meteorites usually break apart high in the atmosphere and are slowed to a gentle fall, landing without making a crater. Scientists did not expect a stony meteorite only a metre or two across to reach the ground fast enough to blast out a crater. Yet Carancas appears to have stayed largely intact and struck at a speed of a few kilometres per second. Studies since have suggested that it may have been unusually strong, or that its fragments stayed close together as they fell.
Illness and alarm. After the impact, some villagers who visited the crater reported headaches, nausea and other symptoms. Rumours spread of a poisonous gas or radiation. Investigations found no radiation. The most likely explanation is that the impact released vapour from the boiling groundwater, which in this area contains naturally occurring arsenic and other substances, or that the smell and the shock of the event caused alarm. The illnesses were short-lived.
Recovering the meteorite. Many fragments of the meteorite were collected by local people and by scientists from Peru and other countries. The meteorite is now held in museum and research collections, and pieces have entered the collectors' market.
Why it matters. Carancas is the only known crater from a stony meteorite whose impact has been witnessed. It showed that small stony bodies can sometimes reach the ground with enough energy to make a crater, an important finding for understanding the hazard from small asteroids. It also showed how quickly people respond to a sudden event in their community, and how important it is for scientists to reach a fall site quickly.
The site today. The crater still exists, though it has been altered by visitors and the weather. It lies on community land, and access requires local permission.
Did you know?
Carancas is the only known witnessed crater made by a stony meteorite.
The crater filled with groundwater soon after the impact.
The meteorite is an ordinary chondrite, the most common type of meteorite.