A close shave this week with an asteroid estimated to be about 100 meters wide is yet another unnerving reminder of how ill-prepared we are for the threat of rogue space rocks.
Scientists with the Brazilian SONEAR survey detected the object, dubbed 2019 OK, on Wednesday and it was soon after confirmed by Ohio State’s All-Sky Automated Survey for Supernovae network.
By the time it was announced, 2019 OK was just hours away from its closest approach – which put it at a distance closer to Earth than the moon.
Thankfully, experts found it poses no immediate threat, and the asteroid zipped by without incident.
But, the surprise appearance has left many feeling unsettled.
‘The lack of warning shows how quickly potentially dangerous asteroids can sneak up on us,’ Monash University astronomer Michael Brown wrote in an essay for The Conversation.
Asteroid 2019 OK passed relatively close to Earth, at about 70,000 kilometers away (43, 496 miles).
For an object of its size, many say that’s a bit too close for comfort.
While it isn’t large enough to bring on an Armageddon-style event reminiscent of the dinosaur-killing asteroid, Brown notes that a moderate-size impact ‘could devastate a city.’
By the time of its closest approach, asteroid 2019 OK would have been bright enough in the sky to be seen with just a pair of binoculars, the astronomer says.
‘Such bright fly-by isn’t often — once per a few years if my memory serves,’ Caltech astronomer YE Quanzhi noted on Twitter.
Since its discovery, scientists have traced the path of asteroid 2019 OK and even retrospectively spotted it in observations gathered back in June.
According to the experts, it will be a few years before it comes around again.
‘2019 OK has a very elliptical orbit, taking it from the asteroid belt beyond Mars to within the orbits of both Earth and Venus,’ Brown says.
‘As each orbit takes 2.7 years, it isn’t always going to pass as close to Earth as it did this time. It will make close approaches in the future, but hopefully not quite this close.’
These smaller objects are what currently remain among the biggest concerns in planetary defense.
NASA estimates it has already found over 90 percent of near-Earth objects measuring one kilometer or larger – which would have catastrophic global effects in the event of a collision.
But, smaller space rocks are much harder to detect.
The space agency has been working to pinpoint NEOs in the 140-meter range, with a goal of identifying at least 90 percent of these objects.
Asteroid 2019 OK, however, reminds us that they can still pop up without warning.
And, though the risk of this and other known objects of its size crashing into Earth may be small, Brown notes, ‘they would be devastating if they did.’