A metal object of unknown origin fell down on Earth in the Brazilian state of Maranhao. The unusual event caused panic among the local population. The ball-shaped, 30-50 kilograms object about one meter in diameter was found on Feb. 22. In December 2011, a similar incident happened in Namibia, where a metal “Teletubby head” weighing 5.9 kilograms and measuring 35 centimeters in diameter hit the...