The Muonionalusta meteorite fell to Earth nearly a million years ago. It comes from the core of an ancient planet or asteroid that broke apart in a collision in space.
Its iron structure bears unique Widmanstätten patterns – a pattern created by extremely slow cooling in weightlessness that cannot be imitated.
It is a class IVA octahedrite, and the first documented find was in 1906, and its discoveries are becoming increasingly rare.