2020 was actually a disaster movie and 2021 doesn’t look much better. As if that wasn’t dystopian enough, there is now a giant asteroid that will pass uncomfortably close, uncomfortably soon.
Asteroid 2001 FO32 will zoom past Earth on March 21 – but wait. There’s no reason to start preparing for doomsday yet, even though it’s big enough and will be close enough to be classified by NASA as a potentially dangerous asteroid (PHA). 2001 FO32 sounds like a nightmare at first. The space rock, whose orbit intersects Earth, will be both the largest and fastest asteroid to pass our home region in 2021. . That’s 21 miles per second.
Wait a while before storing toothpaste and dish soap in your basement. NASA is confident that FO32 will not hit us, despite the scary classification it gave the asteroid. They know something there, because they have been watching the object since 2001 (it can take years and even decades to confirm where something is and where it is going in space). The ratings for a potentially dangerous asteroid make the 2001 FO32 sound much more nervous than it actually is. But first, before anything is officially considered dangerous, it must qualify as a Near-Earth Object (NEO).
Asteroids and comets often end up as NEOs when the gravitational pull of other planets pushes them close to Earth. Most will never again be a dinosaur removal waiting to happen. At some point in its orbit, an object must enter the danger zone less than 1.3 times the distance from Earth to the Sun to be considered a NEO. Earth is 93 million miles from the sun, so whatever it is must be nearly 121 million miles from Earth at any time during its orbit to cross over from just another object out there to NEO status.
Asteroids and other NEOs must be about 150 meters long and sneak within 4.6 million miles of Earth while orbiting potentially dangerous asteroids or, if the threat in question is a comet, potentially dangerous objects. We have one thing that the dinosaurs didn’t have before the Chixculub asteroid hit Earth. NASA and other space agencies are developing asteroid deflection techniques. Finding out how big a dangerous NEO is, along with its shape, mass, structure, and chemical makeup, can help scientists figure out the best way to deflect it.
NASA’s DART mission, starting in July, will experiment with the harmless asteroid Didymus located 18 million kilometers away. There will be one spacecraft bumping into Didymus and moving it out of the way, shifting the trajectory of its moonlet “Didymoon”, and another one to frame the whole thing as it continues.
FO32’s orbit has been studied long enough for NASA to be sure it won’t hit our planet in the face. It is in a very elliptical orbit around the sun, passing our star every 810 days, so a year on this asteroid is slightly more than double what it is here. Its size was determined by how bright it appears, which depends on how the light reflects. It may be larger than 97% of the asteroids, but keep in mind that many asteroids and meteorites are small enough to burn up or at least disintegrate in the atmosphere as they dash toward Earth.
Even at a size that would make the Golden Gate Bridge shudder, it’s still nothing compared to the really big asteroids that lurk in the dark. At least we don’t have to worry about that for the next hundred years.