An asteroid the size of Toronto’s CN Tower is projected to pass near Earth just after the spring equinox, in what will likely be the largest and fastest close approach by a space rock this year.
Or at least, it’ll be the largest and fastest of the asteroids we see coming, because NASA has missed a few in the past.
The asteroid is big enough that it could do some damage if it ever hit, but NASA says it will safely pass us by while putting on a show for stargazers on Earth.
The object, dubbed 2001 FO32, is projected to cruise past Earth on March 21 at a minimum distance of about 2 million kilometres. That’s more than five times the distance from the Earth to the moon.
It’s a little close for comfort by cosmic standards, and near enough to be deemed a “potentially hazardous asteroid” by NASA’s classification system. It’s still much farther away than other near-misses from the recent past, and scientists are confident that it will not change course based on two decades of observations.
“There is no threat of a collision with our planet now or for centuries to come,” NASA says.
Precise measurements of such objects are difficult, and it was initially thought to be a full kilometre wide when it was discovered in 2001. NASA’s asteroid-hunting NEOWISE satellite has since pegged it at a slightly smaller size of about 396-680 metres in diameter. That puts it in the same ballpark as the CN Tower (553 m) in Toronto and One World Trade Center (541 m) in New York, though it doesn’t necessarily have the same dimensions or mass.
Astronomers hope to get a better sense of its size when it passes us by.
“This is the closest predicted approach in 2021 for any moderately large asteroid, where ‘moderately large’ means at least several hundred meters in size,” Paul Chodas, the director of the Center for Near-Earth Object Studies, told CBS News.
NASA says the asteroid will pass at a speed of 124,000 km per hour, which is faster than most other asteroids that encounter Earth. The rock gets its speed from an eccentric orbit around the sun, which causes it to loop above and below the plane of Earth’s orbit.
“As 2001 FO32 makes its inner solar system journey, the asteroid picks up speed like a skateboarder rolling down a halfpipe, and then slows after being flung back out into deep space and swinging back toward the sun,” NASA says.
It completes one loop through the solar system every 810 days.
Many giant space rocks whip past Earth each year without actually hitting the planet. Those that do fall into our atmosphere often burn up on entry, creating streaking fireballs in the sky and occasionally reaching the ground as much smaller versions of the original objects.
An asteroid would have to be truly massive to cause major damage to Earth. The one that wiped out the dinosaurs, for example, was about 16 kilometres in diameter — something that NASA doesn’t often see in Earth’s immediate neighbourhood.
The last significant asteroid to narrowly miss Earth was 1998 OR2, which passed on Apr. 29 of last year. That rock was four times the size of the one heading our way now.
NASA says it has identified more than 95 per cent of all near-Earth asteroids of significant size, and none of them pose a threat within the next century. While the agency has been surprised by big rocks coming out of nowhere in the past, it’s confident that it won’t miss something truly dangerous.
“It is extremely unlikely that any of the remaining undiscovered asteroids of this size could impact Earth,” NASA says.
The largest potentially world-changing asteroid in the forecast is 1950 DA, a 1.3 km-wide asteroid that could hit Earth in 2880.
You and everyone you know will be long dead by then. So who cares, right?