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The probability of an asteroid the size of the Empire State Building hitting the Earth is very slim.
Do not worry. You’ll be dead long before this is even possible. So are your children. Probably all your grandchildren too.
There’s a 1 in 1750 chance, NASA scientists said at a press conference Wednesday. asteroid named BennuSlightly wider than the height of the Empire State Building, it can collide with Earth up to 2300.
That’s actually slightly higher than an earlier estimate of 1 in 2,700 in the shorter timeframe between now and 2200.
“It’s not a significant change,” said Davide Farnocchia, a scientist and lead author at NASA’s Jet Propulsion Laboratory in California. An article published in the journal Icarus. “I’m no more worried about Bennu than I used to be. The probability of impact remains really small.”
In any case, Bennu’s orbit is known with such certainty that the chance of collision for the next century is exactly zero. But the crystal ball becomes more blurry at 2135. That year, Bennu will still miss Earth, but will come pretty close, about 125,000 miles away, or about half the distance from Earth to the moon.
The precise distance becomes crucial because Earth’s gravity will throw Bennu as it passes. If it passes a certain distance at a given time—what planetary scientists call a “gravity keyhole”—then it will be sent into an orbit that can actually intersect with Earth in about half a century.
The most worrying day would be September 24, 2182, but the probability of a bad day would be only 0.037 percent. Bennu is about a third of a mile or half a kilometer wide. This isn’t big enough to cause a planet-wide extinction, but it could cause quite a bit of destruction.
“Generally, you could say the crater size would be 10 to 20 times the size of the object,” said Lindley Johnson, planetary defense officer at NASA. “So a half kilometer object will form a crater that is at least five kilometers in diameter and can be up to 10 kilometers in diameter. But the destruction area will be much larger than that, 100 times the size of the crater. So, an object the size of Bennu affecting the East Coast states. destroys more or less everything on the shore.”
improved possibilities, NASA’s OSIRIS-REX spacecraftHe spent two years studying Bennu closely. The spacecraft left Bennu three months ago and is now returning to Earth to drop samples of rock and dirt it collected from the asteroid for detailed laboratory study by scientists.
While the spacecraft was in orbit around Bennu, Dr. Farnocchia and his colleagues were able to pinpoint the asteroid’s orbit. This allowed them to improve the estimate of Bennu’s position in 2135 by 20 times.
OSIRIS-REX’s observations also made it possible to calculate the small forces exerted on Bennu caused by the heating and cooling of the surface.
Mission managers chose Bennu in part because it’s loaded with types of carbon molecules that may have provided the building blocks for life on Earth. But they also chose it, in part, because Bennu is what’s known as a near-Earth asteroid. Its orbit exceeds Earth’s, and as soon as it was discovered in 1999, planetary scientists were able to see that it poses a potential danger to our planet.
But there may be a greater danger than that. asteroids not yet seen. Dr. About 40 percent of near-Earth asteroids the size of Bennu have not been found, Johnson said.
If an asteroid seems likely to collide with Earth, humanity could try to deflect it into a planet-missing orbit. NASA will conduct an experiment using this technique with an asteroid called Didymos in 2022. Double Asteroid Redirect Test spacecraft to take it out of orbit. The spacecraft is lined up to be launched later in the year.
Dr. Such a deflection would have worked for a faulty asteroid the size of Bennu if there had been decades of advance warning, but would require multiple impactors, Johnson said.
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