An asteroid no bigger than a school bus whizzed past Earth at 18,000 miles per hour on Sept. 7, harmlessly continuing its cosmic journey after paying our planet an exceptionally close visit. The rock, dubbed 2016 RB1, made its closest approach just 25,000 miles from the Earth’s surface. That’s just a tad farther out than the orbit of weather satellites — an extremely close shave, in space rock terms. Scientists spotted it just two days before it passed.
There’s no chance 2016 RB1 will hit us, and even if it did, Earth would barely notice. It would be statistically most likely to explode over an unpopulated area, and it’s too small to make a dent; the asteroid is 25 to 50 feet wide, a range that’s hard to pin down because 2016 RB1 is so small and moving so fast. It’s probably at least 10 feet narrower than the rock that exploded over Chelyabinsk, Russia, in February 2013. Still, this wimpy asteroid is notable for two reasons: its close passage and the fact that scientists saw it at all.
The solar system is full of crumbs left over from the birth of the sun and the planets. Some of them hold clues to the formation of the Earth and, potentially, the beginning of life, which is why NASA just launched a spacecraft to a nearby coal-dark rock called Bennu. Some asteroids hold precious metals, which private companies would like to mine someday for use in electronics and catalytic converters on Earth. And some asteroids occasionally make their way to our planet, where they explode in the atmosphere or excavate giant craters and, sometimes, cause global catastrophes.
NASA and other space agencies are trying to find as many asteroids as they can, but most of them remain unknown to us. Many are too small, too dark, too distant or in the wrong place in the sky for our telescopes to catch them. Yet some of them are big enough to pose a threat to people on Earth, so figuring out where they are is a key part of NASA’s mission.
There is good news: Gigantic space rocks like the one that probably killed the dinosaurs will not arrive anytime soon. Using infrared telescopes in space, as well as sophisticated ground-based telescope networks, scientists are confident they’ve found more than 90 percent of the Earth-killer asteroids out there — the ones about half a mile wide or larger, which would cause global extinctions if they crashed into Earth. None of those threaten our livelihoods in the next few centuries.
But there are plenty of small and mid-size asteroids, and they can do a lot of damage, too. Congress mandated that, by 2020, NASA is supposed to have found 90 percent of asteroids measuring 460 feet across, roughly the size of a football stadium, which would cause regional havoc if not global devastation. Scientists think there are about 25,000 such asteroids, and they have located some 20 percent to 25 percent of them. Asteroid-hunting surveys find about 500 a year, and NASA has said it won’t hit the deadline for that 90 percent mark without more funding. Then there are the house-size and bus-size rocks, like Chelyabinsk and 2016 RB1. More than a million asteroids like those are thought to exist, but scientists have details on maybe 1 percent of them.
by Rebecca Boyle, FiveThirtyEight | Read more:
Image: uncredited
There’s no chance 2016 RB1 will hit us, and even if it did, Earth would barely notice. It would be statistically most likely to explode over an unpopulated area, and it’s too small to make a dent; the asteroid is 25 to 50 feet wide, a range that’s hard to pin down because 2016 RB1 is so small and moving so fast. It’s probably at least 10 feet narrower than the rock that exploded over Chelyabinsk, Russia, in February 2013. Still, this wimpy asteroid is notable for two reasons: its close passage and the fact that scientists saw it at all.The solar system is full of crumbs left over from the birth of the sun and the planets. Some of them hold clues to the formation of the Earth and, potentially, the beginning of life, which is why NASA just launched a spacecraft to a nearby coal-dark rock called Bennu. Some asteroids hold precious metals, which private companies would like to mine someday for use in electronics and catalytic converters on Earth. And some asteroids occasionally make their way to our planet, where they explode in the atmosphere or excavate giant craters and, sometimes, cause global catastrophes.
NASA and other space agencies are trying to find as many asteroids as they can, but most of them remain unknown to us. Many are too small, too dark, too distant or in the wrong place in the sky for our telescopes to catch them. Yet some of them are big enough to pose a threat to people on Earth, so figuring out where they are is a key part of NASA’s mission.
There is good news: Gigantic space rocks like the one that probably killed the dinosaurs will not arrive anytime soon. Using infrared telescopes in space, as well as sophisticated ground-based telescope networks, scientists are confident they’ve found more than 90 percent of the Earth-killer asteroids out there — the ones about half a mile wide or larger, which would cause global extinctions if they crashed into Earth. None of those threaten our livelihoods in the next few centuries.
But there are plenty of small and mid-size asteroids, and they can do a lot of damage, too. Congress mandated that, by 2020, NASA is supposed to have found 90 percent of asteroids measuring 460 feet across, roughly the size of a football stadium, which would cause regional havoc if not global devastation. Scientists think there are about 25,000 such asteroids, and they have located some 20 percent to 25 percent of them. Asteroid-hunting surveys find about 500 a year, and NASA has said it won’t hit the deadline for that 90 percent mark without more funding. Then there are the house-size and bus-size rocks, like Chelyabinsk and 2016 RB1. More than a million asteroids like those are thought to exist, but scientists have details on maybe 1 percent of them.
by Rebecca Boyle, FiveThirtyEight | Read more:
Image: uncredited
