France, Aug. 26 -- At the Fleurance Astronomy Festival in south-west France, 50 volunteers have gathered across four freshly cut fields of wheat. The group, kitted out in caps, rucksacks and trainers, includes space enthusiasts as well as families with young children.

The volunteers have been told that a meteorite fell to Earth during the night, just a few hundred metres from where they are standing.

"We saw a huge flash of light at an altitude of 30 kilometres, then the fireball broke into many pieces. The aim is to find them," said planetary scientist Sylvain Bouley, who is leading the search.

This meteorite hunt is actually just an exercise, a fact the volunteers are aware of. An hour before the public arrived, Bouley hid 20 meteori...