Until now, scientists didn’t know for sure where most of the stuff around us came from. Now, they do.
Silica, or silicon dioxide (SiO2), is just about the most abundant thing here on the outer shell of Earth. It makes up most of the planet’s crust by mass — about 60 percent, according to NASA. It’s the main thing in sand at the beach. It’s common in dirt and clay. It makes up most of the stuff in sandstone and quartz, and it’s a critical ingredient in feldspar (a super common sort of rock). Granite has a lot of it. Humans mix it into cement and melt it into glass. It’s also one of the more common molecules in the universe. And until recently, scientists had some good theories as to where it came from, but they weren’t sure.
Now, according to NASA, they know: All this silica around us was born in supernovas that ripped apart “AGB stars” — a technical term for mid-sized stars not unlike our sun, but in the last millenia of their stellar lifetimes.