If you were told that the odds of something were 3.1%, it really wouldn't seem like much. But for the people charged with protecting our planet, it was huge. On February 18, astronomers determined that a 130- to 300-foot-long asteroid had a 3.1% chance of crashing into Earth in 2032. Never had an asteroid of...

This is today's edition ofThe Download,our weekday newsletter that provides a daily dose of what's going on in the world of technology. Inside the most dangerous asteroid hunt ever If you were told that the odds of something were 3.1%, it might not seem like much. But for the people charged with protecting our planet,...