NASA spacecraft deflected an asteroid to save Earth

NASA spacecraft deflected an asteroid to save Earth


NASA said Tuesday it managed to deflect an asteroid in a historic test of mankind’s ability to stop an incoming cosmic object from destroying life on Earth.

The refrigerator-sized DART (Double Asteroid Redirection Test) impactor intentionally smashed into the lunar asteroid Dimorphos on September 26, sending it into a smaller, faster orbit around its big brother Didymos, NASA chief Bill Nelson said.

“DART shortened the orbit from 11 hours 55 minutes to 11 hours 23 minutes,” he said. Accelerating Dimorphos’ orbital period by 32 minutes exceeded NASA’s own expectation of 10 minutes.

“We showed the world that NASA means business as a defender of this planet,” added Nelson.

The asteroid pair orbits our sun every 2.1 years and poses no threat to our planet.

But they are ideal for investigating the “kinetic impact” method of planetary defenses if an actual approaching object is ever spotted.

DART’s success as a proof-of-concept has made science fiction a reality – particularly in films like Armageddon and Don’t Look Up.

Astronomers were delighted with stunning images of matter spreading thousands of kilometers after the impact – images collected by Earth and space telescopes, as well as a minisatellite that traveled to the zone on DART.

– pseudo comet –

Thanks to its temporary new tail, Dimorphos has transformed into an artificial comet with a diameter of 160 meters (530 feet), or about the size of a great Egyptian pyramid.

But quantifying how well the test worked required analysis of light patterns from ground telescopes, which took a few weeks to become visible.

The binary asteroid system, which was around 6.8 million miles (11 million kilometers) from Earth at the time of impact, is only visible as a single point from the ground.

Before the test, NASA scientists said the results of the experiment would show whether the asteroid is a solid rock or more like a “garbage heap” made of boulders bound by mutual gravity.

When an asteroid is more solid, the momentum imparted by a spacecraft is limited. But when it’s “fluffy” and a significant mass is pushed at high speed in the opposite direction of impact, there’s extra thrust.

Never photographed before, Dimorphos appeared as a patch of light about an hour before impact.

Its egg-like shape and jagged, boulder-strewn surface finally came into focus in the final moments as DART hurtled toward it at approximately 14,500 miles (23,500 kilometers) per hour.

– mass extinction –

Very few of the billions of asteroids and comets in our solar system are considered potentially dangerous to our planet, and none are expected in the next hundred or so years.

But wait long enough and it will happen.

For example, the geological record shows that 66 million years ago, a six-mile-wide asteroid struck Earth and plunged the world into a long winter that led to the mass extinction of dinosaurs along with 75 percent of all species.

An asteroid the size of Dimorphos, on the other hand, would only have regional effects, such as devastating a city.

Kinetic impact with a starship is just one way to defend the planet, albeit the only method possible with current technology.

Should an approaching object be detected early, a spacecraft could fly alongside it long enough to redirect its path, using the ship’s gravitational pull and creating what is known as a gravity tractor.

Another option would be to launch nuclear explosives to deflect or destroy an asteroid.

NASA believes the best way to use such weapons would be remotely to transmit power without blasting the asteroid to pieces, which could further endanger Earth.

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