How To Discover Your Own Massive Meteorite Crater (And Still Work From Home)

A new citizen science project called Vigie-Cratère is inviting “citizen scientists” to travel Earth in search of impact craters to help scientists better reconstruct the history of collisions with Earth. 

Earth has been bombarded since the beginning, but only about 200 terrestrial impact craters are known by science—and over half are in Europe, North America and Australia. Most of the world’s large 6km+ craters have probably already been discovered, but scientists estimate that dozens of small craters above 1 km in diameter—and likely a few hundred smaller than 1km—have yet to be found. 

The source of many suspected craters is, of course, satellite images, but members of the public are being asked to compare these with new layers of topographic data, so-called “shaded relief” that can reveal circular depressions that are otherwise invisible if only satellite images are studied.

So far almost more than 3,600 potential meteorite impact craters have been discovered by users of Vigie-Cratère.

How has topographic data changed recently to make this possible?

“In the last couple of years not only the resolution of topographic data have been greatly improved, but also the coverage,” said Ludovic Ferrière, curator of the meteorite and impactite collection at the Natural History Museum Vienna (Austria). Until recently some parts of Earth were not covered, or only partially so. “However, the innovative aspect here is that our protocol is based on topographic data, shaded relief, capable of revealing circular depressions invisible to satellite imagery.”

Why are most known craters in Europe, North America and Australia?

“The reason is mainly because extensive search campaigns took place in these parts of the Earth,” said Ferrière. “Not only is access problematic in some parts of the Earth, but also the vegetation can make things more complicated. On top of that, the older the rocks exposed at the surface are, the more you expect to find impact craters.”

Why citizen science works best

“One of the motivations to ask people help is not only for the search on the platform, but also to ask that they post information and photographs of the rocks if they happen to live or travel nearby a suspected crater,” said Ferrière.

Are the depressions always circular?

“Yes, we are looking for circular depressions or circular features, but than depends on the post-impact geological history of the area where they are located,” said Ferrière. “They are expected to be more or less eroded and they can also be deformed.”

Do ‘citizen scientists’ get naming rights?

Possibly. Naming of impact craters on Earth is usually based on geographical names, but there are no specific rules. However, Vigie-Cratère is about detecting possible impact structures for further investigations, not for naming. “Field work campaigns will be necessary to confirm the impact origin of these structures—it is a much more complicated and long term adventure,” said Ferrière, who stresses that funding will be required for the follow-up field campaigns.

The biggest and the best impact structures on Earth

• The largest visible confirmed impact crater on Earth is the Vredefort impact structure in South Africa. It’s about 300 km in diameter.
• The largest “invisible” confirmed impact crater on Earth is the Chicxulub impact structure in Mexico. About 200 km in diameter, this is thought to be the “dinosaur-killer” crater.

The Meteor Crater (Barringer crater) in Arizona is one of the most impressive and easily accessible.

• The Charlevoix impact structure in Quebec.
• The Rochechouart impact structure in France.

Vigie-Cratère is part of the Vigie-Ciel program supported by the National Museum of Natural History in partnership with the University of Paris Saclay, IRD, Paris Observatory, Universcience, Grenoble Alpes University, the Pythéas Institute, the Natural History Museum Vienna, and the CNRS. 

Wishing you clear skies and wide eyes.