Metal from space
Some meteorites are made almost entirely of metal. Where did it come from?
Most meteorites are stony. But some are made of metal, mostly iron with some nickel. They are called iron meteorites.
They are very heavy for their size. A magnet sticks to them strongly.
The metal came from inside an asteroid. Long ago, some young asteroids got so hot that they melted. The heavy metal sank to the middle and made a metal core, a bit like the core deep inside Earth.
Later, other asteroids smashed into them and broke them apart. Pieces of the metal cores flew off into space. Some of them have reached Earth.
When scientists cut an iron meteorite, polish it, and treat it with a special acid, a beautiful criss-cross pattern often appears. It is made of metal crystals that grew very slowly as the core cooled, over millions of years. Only adults working safely in a laboratory do this.
An iron meteorite is the only way we can hold a piece of a planet-like core in our hands.
The criss-cross pattern in many iron meteorites is called a Widmanstätten pattern. It is hard to say, but fun to try: VID-man-shtet-en.