Humans won’t go the way of the dinosaurs for at least 1,000 years, according to a new study of large asteroids lurking nearby.
Researchers from the University of Colorado, Boulder and NASA have analyzed nearly 1,000 near-Earth objects (NEOs) larger than a kilometer in size, but unlike the typical model that assesses their risk over a century, the team has looked ahead. forward millennia.
“In general, asteroid impacts capable of causing significant damage to Earth are extremely unlikely,” said NASA’s Dr. Davide Farnocchia, speaking with MIT Technology Review. ‘Just in case, we are doing our due diligence.
“We came up with a less computationally intensive approach to take a look at a longer time interval.”
About 3,000 new NEOs are discovered each year by survey telescopes that scan the night sky for potential threats.
However, although asteroids follow known orbits around the Sun, small uncertainties in their position can have a major effect on their trajectory, as can the gravitational effects of nearby planets. This requires careful monitoring and route prediction.
Farnocchia, of NASA’s Center for Near-Earth Object Studies at the Jet Propulsion Laboratory in California, said that by identifying the small portion of each asteroid’s orbit that would bring it close to Earth, they could assess the possibility of an impact over a much longer period. timeline
“This is good news,” said lead author Oscar Fuentes-Munoz, of the University of Colorado, Boulder. “To the best of our knowledge, there is no impact in the next 1,000 years.”
The study, which has been accepted for publication in the astronomical diary, identified the asteroid with the highest risk of collision. Named 1994 PC1, the stony, kilometer-wide asteroid was found to have a 0.000151% chance of passing within the orbit of the Moon, ten times the risk posed by any other asteroid studied.
How many asteroids are out there?
According to NASA, there are 1,282,699 known asteroids.
Sometimes called minor planets, they are rocky, airless remnants left over from the early formation of the solar system around 4.6 billion years ago. Most are found in the asteroid belt between Mars and Jupiter.
The largest known asteroid is Vesta, about 329 miles across.
The total mass of all asteroids combined is less than that of Earth’s Moon.
“It’s still not likely to crash,” Fuentes-Munoz said. “But it will be a very good scientific opportunity, because it will be a huge asteroid that will be very close to us.”
However, the study has not evaluated the smallest asteroids that are still capable of destroying a city, those measuring more than 140m across. Fuentes-Muñoz told The MIT Technology Review that NASA’s NEO catalog is 40% complete.
“It depends on how many there are, which is really uncertain,” he said. We are not sure. But there is hope that the new surveys of the sky will provide us with a much higher integrity rate.
NASA last year successfully tested its planetary defense system Double asteroid redirection test (dart), crashing a rocket into an asteroid and changing its trajectory.
Just in case.
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