As reported NASA Center for Near-Earth Object Research, About 26,115 asteroids have orbited the Earth since 1990. Of these, 888 are more than a kilometer in diameter, making it two and a half times taller than the Empire State Building in New York.
But when was the last time an asteroid hit Earth?
According to Marina Prosovic, Scientist at NASA’s Jet Propulsion Laboratory, the answer depends on your definition of being struck by an asteroid. Prosovic said on the show that small asteroids will always hit the Earth. “We asked a NASA scientist“From NASA, many of them have not even reached the Earth’s surface, meaning there is no impact on land or sea or it will have no serious consequences.
NASA has named any asteroid 140 meters or more. It approaches the planet as a dangerous asteroid (PHA) due to its potential for catastrophic damage to Earth. In the last century, eThe most important asteroid to hit Earth was the size of a small building that flew over Russia in 2013. The asteroid crashed 20 km away. Above the ground, numerous meteors are scattered over the Russian city of Chelyabinsk.
But when was the last asteroid to have a major impact on our planet, leaving craters in its wake and causing massive catastrophe? “We have to go backwards for such an event. Finding those old grooves is not easy. For now, they may be sedimentary or at the bottom of the ocean.Prosovic responded.
In the first years of the earth,The planet was bombed furiously by massive ancient asteroids, 10 times more than previously believed, and may have delayed its ability to support life on the planet. Even today, however, asteroids pass over Earth unnoticed. In October, an asteroid Earth was just 3,000 kilometers from the planet’s surface, less than a quarter of the planet’s diameter, but no one realized it until it was real.
But the danger of conflict remains. Another asteroid About 330 meters long, the size of the Eiffel Tower, According to NASA’s Asteroid Tracker, it is heading towards Earth and is expected to pass near in December.
According to scientific calculations, It will travel 3.9 million kilometers from Earth. This is one of the four closest approaches to the earth in this century Asteroid 4660 Nerius 330 meters in diameter, it was discovered in 1982 and orbits the sun every 664 days.
Occurs when an asteroid moves close to Earth NASA is about to launch a project that will be described as the world’s first planetary defense mission. That task, called DART (Dual asteroid redirection test) Includes A spacecraft collided with a small asteroid in an attempt to change its orbit slightly.
Nereus comes within 3.9 million kilometers of Earth, which is slightly 10 times the average distance between the Earth and the Moon. Although classified as “Dangerous Possibility”, Chances are it’s one The hidden threat to our planet is less because of the distance from our planet.
Nerius also went near our planet 2002, And will do it again 2060 And 2071. In the event 2060, Nereus is predicted to pass 1.2 million km from Earth, Three times the average distance between the Earth and the Moon.
Asteroid expected 99942 Apophis, About the same diameter as Nerius, passed 32,000 km from Earth in April 2029. In March of this year, NASA has released a statement assuring the world that its calculations “will have no impact” [de Apophis] For at least the next 100 years ”.
This does not prevent the agency from working Ways to protect the Earth when a planet collides with a large object in space.
A spacecraft planning to collide with a small asteroid during a voyage DART Has a publishing site on Vandenberg Space Base, California and will be released on November 23rd.
The spacecraft will orbit the small asteroid Dimarpos, Which orbits a large asteroid Didimos, None of these are a threat to the Earth.
The goal is to show it A spacecraft can automatically navigate to the target asteroid and “dynamically affect” it.
“Then, using ground-based telescopes to measure the effects of impact on the asteroid system, This task will improve the modeling and prediction skills and help better prepare for the real asteroid threat If it is ever discovered, ”NASA said.