A mining engineer spent decades proving an Arizona crater came from space

When Daniel Barringer studied the 1.2km-wide crater near Winslow, Arizona in 1903, most geologists assumed it was an extinct volcano. He argued it was punched out by an iron meteorite and spent the rest of his life digging for a fortune in buried metal he never found. Later analysis of shocked quartz proved him right — it's the first crater on Earth ever confirmed to be an impact site, formed roughly 50,000 years ago.

— Wikipedia contributors, Meteor Crater — Barringer Crater, Arizona