News has emerged today of a mysterious object that fell out of the sky about 750 km north of Windhoek in November this year. The object is a metal sphere, about 35 cm in diameter, 110 cm in circumference and weighing 6 kg, apparently made of two metal hemispheres welded together. There is nothing mysterious about the materials used, and the object is definitely something that could be made with human technology. Nevertheless nobody seems to know quite what the object is, or who made it. The Namibian authorities have been in contact with both NASA and the European Space Agency, but neither have been able to identify the object.
The mysterious object.
Actually, as mysterious objects go, this one is not very mysterious. It is clearly a part of a satellite, intended to hold some sort of liquid, probably fuel for an instrument. Fuel tanks on satellites tend to by spherical and very solid, as this is the best structure for coping with a liquid sloshing about in changing gravity fields with zero pressure on the outside. It is also an excellent shape for surviving re-entry through the Earth's atmosphere, enabling the tanks to survive re-entry when the rest of the satellite burns up. This is not the first mysterious sphere to fall from the sky, previous examples have been recorded in Australia, Brazil and the US. Many more probably fall into the sea, remote locations where they are never found, or in countries that will not publicize the find.