A meteorite which ploughed into the Peruvian countryside last year should have shattered and dispersed long before reaching the ground. That is the conclusion of scientists who have been examining samples of the space rock and the 15m-wide crater it dug out in Carancas last September. The discovery of a water-filled hole, following reports of a fireball in the sky, made headlines around the world. Now experts say the event challenges conventional theories about meteorites.