Internal emails from NASA reveal how experts didn't detect a football-field-sized asteroid until it was about to narrowly miss Earth this summer.
In emails obtained by BuzzFeed News via a Freedom of Information Act request, NASA officials asked each other how the asteroid, named "2019 OK," had escaped detection until an observatory in Brazil reported it on July 24 - the same day it passed our planet.
In the email chain, Paul Chodas, manager of NASA's Centre for Near Earth Object Studies, posed two questions: First, "why was 2019 OK not discovered by one of the major NASA surveys?" and second, if the Brazilian observatory hadn't caught the asteroid, "is it possible it could have escaped discovery completely?"
"BTW, all, just for context, it appears that 2019 OK is by far the largest asteroid [to] pass this close to Earth in the last century!" reads one subsequent email from Planetary Defense Officer Lindley Johnson.
NASA experts determined that a combination of factors ultimately caused the agency to miss it, including the position of the moon, bad weather and the slow-moving nature of the asteroid.
"So, was this just a particularly sneaky asteroid?" Chodas asked. "I wonder how many times this has happened without the asteroid being discovered at all."
Johnson said in one email that this miss was an "interesting story on the limitations of our current survey network."
The incident highlights Congress' long-running failure to fund reliable equipment to monitor "potentially hazardous" asteroids, BuzzFeed reported.
NASA experts also expressed frustration over the way Australian scientists and the media sensationalised the asteroid, describing it as a "city killer" to the Sydney Morning Herald.
"It might be helpful to ask them to think before they speak (of nuclear explosions and such..)," reads one email from a redacted sender.
"All the rest - including WaPo ― is simply repetition... This story also says to me that we have to keep up our good work of calming down asteroid rhetoric. City-killers, nukes, etc."
According to NASA's informational statement about OK 2019 from last month, had the asteroid hit Earth, it would have created "localised devastation to an area roughly 50 miles across." If it had fallen in the ocean, it would have been a "bad day for any sailing vessels in the vicinity," but it's doubtful it would have caused a tsunami.
The chances of an asteroid of this size hitting Earth is "only on the order of once every several thousand years," Chodas said.