Vietnam defense officials reportedly are investigating three mysterious metal spheres that apparently dropped out of the sky and crashed in a rural area of the country's north last weekend.
Local residents reported hearing "what sounded like thunder, despite no signs of rain," before venturing outside and finding the orbs. They range from 15 to 40 inches in diameter.
One landed near a stream in Tuyen Quang province, another in the garden of a home in neighboring Yen Bai province. A third — the smallest, only 9 ounces — hit the roof of a house. Fortunately no one was injured.
The defense ministry believes the spheres are compressed-air tanks that ended up as space debris, but whether they originated from a missile or some other aircraft is not known, Thanh Nien News reported.
Nguyen Khoa Son of Vietnam's State Space Science and Technology Program told Vietnam Net: "This may be the result of a failed launch of satellite."
Now that they have landed, the balls pose no danger — they contain no explosives. Russian writing on the surface of the orbs suggests the balls were manufactured for Moscow's air force or space program, although they could have been sold to another country.