Michael Schirber in Space.com:
The asteroid that struck the Yucatan Peninsula 65 million years ago presumably initiated the extinction of the dinosaurs. The huge collision also unleashed a worldwide downpour of tiny BB-sized mineral droplets, called spherules.
The hard rain did not pelt the dinosaurs to death.
But the planet-covering residue left behind may tell us something about the direction of the incoming asteroid, as well as possible extinction scenarios, according to new research. The falling spherules might have heated the atmosphere enough to start a global fire, as one example.