The Internet lit up with reports last week that a big rock was on a path to nearly strike the Earth on Monday night, Feb. 17. This was not true. But it made for a grabby headline. As in:
“An Asteroid Will Almost Hit the Earth Tonight” (from Motherboard).
The British papers really went to town on this story. The Guardian ran a piece headlined “Asteroid 2000 EM26: ‘potentially hazardous’ space rock to fly close to Earth.” Online, the story has a frightening illustration of a glowing rock plunging toward the Earth.
What did happen is that a rock discovered in 2000 and believed to be roughly 900 feet in diameter, passed by the Earth at a distance of at least 2.1 million miles. That’s nearly nine times the distance to the moon. Is that “uncomfortably” close? I’d say: Not really. And it’s not really news, because rocks of that size pass that close to the Earth multiple times a year – and have been doing so for billions of years.
Don Yeomans, the head of the Near Earth Object tracking program at NASA’s Jet Propulsion Laboratory, told the Los Angeles Times that a rock that size can be expected to pass that close about once every six months. As you go down in the scale toward smaller rocks, you have a commensurate rise in the frequency of these rocks’ “nearly hitting” the Earth.
So why was this one newsy? Because the news business is a quirky beast. The folks at Slooh, a “community” telescope service that streams stuff on the Internet, said they would be live-streaming observations of this “potentially hazardous asteroid,” named 2000 EM26. That announcement raced around the Internet – as if we all needed to tune in to see if the Earth would be struck.
But the event was a dud. The Slooh telescope failed to detect 2000 EM26 as it passed the Earth. There was just dark sky. It’ll probably turn up in subsequent observations. Because these things move really fast relative to the Earth and are small and dark, they can be hard to spot.
The failure to track the asteroid that was supposedly hurtling toward Earth did little to calm things. The Independent, another British newspaper, blared: “Asteroid 2000 EM26 ‘as big as three football fields’ hurtles past Earth.” With that is a stunning photograph of the fireball trail of the asteroid that exploded above Chelyabinsk, Russia, last February. The caption says: “Slooh Space Camera tracked the asteroid as it raced past at 27,000 mph.”
Reuters ran a story with this headline: “Earth marks close encounter with enormous asteroid.”
Well, “close” is a squishy term. Perhaps I’m a little jaded. For people of my generation, 2.1 million miles is still a long way away.
Killer rocks are out there, and we should try to detect them. Arguably we’re not investing enough money and technology in that search. But what we can’t do is lose our minds every time someone shouts that an asteroid is coming – because there are rocks all over the place and they’re part of Earth’s environment in space.
JPL keeps a list of known near-Earth objects that could conceivably pose a threat. Some will come close, but none of the big rocks discovered so far are known to be on a trajectory to hit the Earth in the foreseeable future. (There are uncertainties involved, so an impact can’t be completely ruled out in some cases.) Scientists are confident that we’re not going to suffer a replay in our lifetime of the kind of event that polished off the non-avian dinosaurs 66 million years ago. The frequency of impacts of smaller rocks, such as the one in Chelyabinsk, is the subject of much discussion. Once every 30 years, maybe?
One of our challenges in the technological, scientific age is to sort through a long list of complicated risk factors. We have to figure out what’s worth worrying about and what is exceedingly improbable. Here’s my hunch: The thing that’s going to get us, one day, isn’t going to be something on anyone’s radar.
