Three strange metal spheres fell from the sky in Vietnam's Tuyen Quang province. They range in size and weight, with the smallest at 250 grams and the largest at 45 kilograms. According to the Ministry of Defense, they are likely compressed air tanks from an aircraft or rocket. That said, Nguyen Khoa Son of the National Research Program on Space Science and Technology suggests that they could be debris from a failed satellite launch. Apparently the balls were made in Russia.