Test a rock like a meteorite hunter
The question
Which simple tests best tell an ordinary rock from a meteorite?
Most rocks people think are meteorites are not. Hunters use a set of quick checks: magnetism, how heavy it is for its size, a dark crust, and the colour of its streak.
Equipment
- Six to ten different rocks, including some dark, heavy-looking ones such as basalt or slag if available
- A magnet, a kitchen scale and a measuring jug of water
- An unglazed white tile (the back of a bathroom tile) for streak tests
- A hand lens
Method
- For each rock, run through the site's rock checker: Does a magnet stick? Is it heavy for its size? Is there a thin dark crust? Are there bubbles or holes? What colour streak does it leave on the tile?
- Record every answer in a table.
- Decide which rocks pass most checks, and which test ruled out the most rocks.
- What to measure
- A results table of every check for every rock, and the number of rocks each test ruled out.
- How to present it
- A chart showing which tests were most useful, photos of your rocks, and advice for someone who thinks they have found a meteorite.
- Take it further
- Compare your rocks with the meteor-wrongs gallery. Which look-alikes fooled you?
Safety
Never break, file or heat a rock. Streak tests are done gently on the tile, with the rock held flat.