Carancas crater

Impact

It happened in 11:40:14 local time, 15th September 2007. Local people saw a bright flash, heard a deafening explosion (it was well heard also in the 10 km distant Desaguadero town), and soon a mushroom cloud raised above the ground. Some locals thought that army of Chile has attacked Peru.

Earth trembled, windows in the 1.3 km distant Huanocollo were shattered – most likely by the earthquake and not an explosion. An empty shack some 120 m west from the impact was bombarded by pieces of soil – but was not damaged heavily.

A man riding a bicycle some 100 m from the impact site fell down and was dizzy from all the things happening around – but his eardrums were not ruptured. Pieces of soil flew up to 350 m far.

Crater

The impact created in the soft soil a 13.5 – 14.2 m wide crater, 4.5 m deep, with a 1 m high rim around it. Earth and plants were scorched around the impact site.

In a few minute’s time the groundwater entered the crater and started to boil. According to locals, it boiled approximately for half an hour.

Ar was filled with fetid smells.

Mysterious illness

Soon locals rushed towards the site of impact to see this amazing natural spectacle. Some believed that the meteorite could have high value and were searching for it – and they really found many pieces around the crater. In total, some 600 people visited the place soon after the impact.

Some days later things took an unexpected turn. More and more people became ill – they got nausea, vomit, diarrhea, headaches, dermatitis. Some of the worst affected were 8 police officers who spent more time than others at the crater. In total some 200 people became ill – although it is possible that some part of them rushed to hospitals after hearing rumors that victims of the meteorite can get free medicine and in fact, they were not THAT ill.

Happily some days later the health of people improved – and now all these events seem to be much exaggerated.

It is not entirely clear what caused this illness. One hypothesis says that this is caused by the arsenic in the vapor – reportedly local groundwater contains much arsenic. The urine of some ill people contained much arsenic indeed.

Others deny this theory – the amount of arsenic in local groundwater is not too high. Another explanation is that people inhaled the vapor of meteorite itself. Chondrite can contain troilite – a sulfurous mineral that could be a hazard to health.

Whatever are the reasons – Peruvian experience shows that a visit to a fresh meteorite impact site can be hazardous to health.

Hyperfast chondrite?

Soon, on September 20, Peruvian scientists reported that in Carancas took place meteorite impact.

Research continues, but now it looks like some 7 – 12 t heavy (1.6 – 2 m in diameter) chondritic meteorite (H4-5 chondrite) entered the atmosphere with a speed of some 12 – 17 km per second.

As it was going through the atmosphere from east to west, it lost part of its mass and slowed down to some 3 – 6 km/sec.

The ground was hit by approximately 0.3 – 3 t heavy, 0.5 – 1.1 m large meteorite and there was released energy with an equivalent of 1 – 3 t TNT.

Pieces of this meteorite were found nearby, up to 200 m far from the crater, small meteorite grains are mixed in the soil as well.

Scientists were puzzled by the fact that meteorite was hot – in general, such meteorites are cold after their fall. Now it known that such relatively small meteorites can cross the atmosphere without dividing into several pieces.

New landmark

People in Carancas village have decided to preserve this amazing landmark. It is covered with a temporary tent now and there is planned to build a small museum over it.

This shows how fast things can change. In summer 2007 these empty fields near Carancas were of no interest to the outside people. Then in some minutes, everything changed and… now we got another landmark!

Estimates show that meteorites of such size fall on Earth yearly – but most of them disappear in the sea or remain unnoticed in remote areas.

References

1. G.Tancredi, J.Ishitsuka, P.H.Sschultz, R.S.Harris, P.Brown, D.O.Revelle, K.Antier, A.Le Pichon, D.Rosales, E.Vidal, M.E.Varela, L.Sánchez, S.Benavente, J.Bojorquez, D.Cabezas, and A.Dalmau. A meteorite crater on Earth formed on September 15, 2007: The Carancas hypervelocity impact. Meteoritics & Planetary Science 44, Nr 12, 1967–1984 (2009).

Carancas crater is included in the following list: