Researchers say they finally know why slabs of glass litter this desert: An ancient, exploding comet

An ancient fireball that blasted by a massive desert in Chile some 12,000 years ago created slabs of twisted glass that measure up to a foot and a half in length.

That’s according to a newly published study that called the objects the “first clear evidence” of glass created by a comet – or comets – exploding at a low altitude just above the Earth’s surface.