Back in my school days we were taught that only meteorites made of metal stayed intact enough to cause damage on the ground.
Not quite so. Look at this crater:
Peru meteorite may rewrite rules
Usually, only meteorites made of metal survive the passage through Earth’s atmosphere sufficiently intact to scoop out a crater.
But the object which came down in the Puno region of Peru was a relatively fragile stony meteorite. During the fiery descent through Earth’s atmosphere, these are thought to fragment into smaller pieces which then scatter over a wide area.
Yet pieces of the estimated 1m-wide meteorite are thought to have stayed together during entry, hitting the ground as one.
rofessor Schultz believes fragments from the Carancas meteorite, which crashed to Earth on 15 September last year, may have stayed within the speeding fireball until they struck the ground.
This might have been due to the meteorite’s high speed.
At the velocity it was travelling, fragments could not escape the “shock-wave” barrier which accompanies the meteorite’s passage through the atmosphere.
Instead, the fragments may have reconstituted themselves into another shape, which made them more aerodynamic. Consequently, they encountered less friction during their plunge to Earth, holding together until they reached the ground.
The meteorite was travelling at 15,000 mph when it hit the ground. It was sheer luck that it didn’t hit a large metropolitan area.
Some think the meteorite doens’t make sense; There’s even a Spoof Peru Meteorite Crater Hit by New Meteorite, coining the word meteorwrongs, which might even explain all the people who got sick last year while visiting the site.