An asteroid big enough to potentially ruin human civilization has flown by the Earth, missing us by an astronomical whisker.
Known as Florence, the 4.4km-wide rock missed us by only 4.4 million kilometres - which doesn't sound very close, until you see it illustrated in an image provided by NASA
"Florence is the largest asteroid to pass by our planet this close since the NASA program to detect and track near-Earth asteroids began," Paul Chodas, manager of NASA's Center for Near-Earth Object Studies, said last week.
Named after Florence Nightingale, Florence was first spotted in 1981. Saturday's fly-by is the closest it's come since the 1800s, and isn't expected to swing by again until after 2500.
It's large enough to be visible using small telescopes.
The asteroid that killed the dinosaurs was about 10km across. To wipe out all life on Earth, it's estimated an asteroid would need to be about 60km across.