Scientists think the Earth is overdue for a reboot of Armageddon, or rather they think the planet is just about due for another massive asteroid strike like the one that wiped out the dinosaurs . Those scientists who may or may not also be Bruce Willis enthusiasts almost got their wish when an asteroid about the size of a football field hurtled just 40,400 miles over Earth in late July. It was the largest space rock to come so close in a century .

But perhaps more alarming than the flyby itself is how much it caught NASA by surprise. “This one did sneak up on us,” one NASA expert wrote in an internal email, according to internal agency documents obtained by BuzzFeed News.

The asteroid, given the name 2019 OK, as if to reassure the astronomers, was a near-miss space-wise, whizzing past at a distance that is roughly five times closer to Earth than the moon—and thank the stars it did miss. “If 2019 OK had entered and disrupted in Earth’s atmosphere over land, the blast wave could have created localized devastation to an area roughly 50 miles across,” according to a news release that NASA’s Jet Propulsion Laboratory sent out when they finally noticed the giant rock hurtling at our planet.

“This object slipped through a whole series of our capture nets,” Paul Chodas of JPL wrote in an email obtained by BuzzFeed two days after the asteroid zipped past, noting that it was a “sneaky” little space rock.

While NASA had some excuses for why it missed it, this is not a great start for the much ballyhooed Planetary Defense Coordination Office (PDCO), whose purpose was to “find and characterize asteroids and comets that pass near Earth’s orbit around the sun” and then send Bruce Willis up to blast it (or so we think).