A remarkably large part of science is just noticing that what you have isn’t what you expect. 

Meteorites can do a really good job of pretending to be regular rocks, but they aren’t, and when we can spot them for what they are, the science inside them allows us to get at information we could otherwise only get by sending spacecraft out to collect samples. 

While a lot of meteorites go uncollected, sometimes we get lucky, the meteors are seen falling to Earth, and we can follow the fireball in the sky to the rocks on the ground. Such was the case with the Allende Meteorite which exploded over the Chihuahuan desert in 1969 and scattered two tonnes of material across the landscape. This fragmented space rock is a mix of metals, minerals, and even glass beads that formed in the earliest days of our forming solar system. 

The structure of these beads reveals the conditions under which they were formed, and these beads describe violent collisions followed by rapid cooling at a rate of 500 degrees Celsius per hour! According to Nicolas Dauphas, project principal investigator, one scenario that fits would be massive shockwaves passing through the early nebula: Large planetary bodies nearby can create shocks, which would have heated and then cooled the dust as it passed through.

These early shocks may be responsible for the loss of somewhat volatile elements like potassium and rubidium in the Earth, where they don’t exist in expected amounts. It turns out there is a lot to be learned from glass beads from space!

More Information

The University of Chicago press release

“Imprint of chondrule formation on the K and Rb isotopic compositions of carbonaceous meteorites,” Nicole X. Nie et al., 2021 December 1, Science Advances