NASA to deflect asteroid in check of ‘planetary protection’

In the 1998 Hollywood blockbuster “Armageddon,” Bruce Willis and Ben Affleck race to save lots of the Earth from being pulverized by an asteroid.

While the Earth faces no such speedy hazard, NASA plans to crash a spacecraft touring at a velocity of 15,000 miles per hour (24,000 kph) into an asteroid subsequent yr in a check of “planetary defense.”

The Double Asteroid Redirection Test (DART) is to find out whether or not that is an efficient method to deflect the course of an asteroid ought to one threaten the Earth sooner or later.

NASA supplied particulars of the DART mission, which carries a price ticket of $330 million, in a briefing for reporters on Thursday.

“Although there isn’t a currently known asteroid that’s on an impact course with the Earth, we do know that there is a large population of near-Earth asteroids out there,” mentioned Lindley Johnson, NASA’s Planetary Defense Officer.

“The key to planetary defence is finding them well before they are an impact threat,” Johnson mentioned. “We don’t want to be in a situation where an asteroid is headed towards Earth and then have to test this capability.”

The DART spacecraft is scheduled to be launched aboard a SpaceX Falcon 9 rocket at 10:20 pm Pacific time on November 23 from Vandenberg Space Force Base in California.

If the launch takes place at or round that point, affect with the asteroid some 6.8 million miles from Earth would happen between September 26 and October 1 of subsequent yr.

The goal asteroid, Dimorphos, which implies “two forms” in Greek, is about 525 toes in diameter and orbits round a bigger asteroid named Didymos, “twin” in Greek.

Johnson mentioned that whereas neither asteroid poses a menace to Earth they’re excellent candidates for the check due to the flexibility to look at them with ground-based telescopes.

Images will even be collected by a miniature camera-equipped satellite contributed by the Italian Space Agency that will likely be ejected by the DART spacecraft 10 days earlier than affect.

‘A small nudge’

Nancy Chabot of the Johns Hopkins Applied Physics Laboratory, which constructed the DART spacecraft, mentioned Dimorphos completes an orbit round Didymos each 11 hours and 55 minutes “just like clockwork.”

The DART spacecraft, which is able to weigh 1,210 kilos on the time of affect, won’t “destroy” the asteroid, Chabot mentioned.

“It’s just going to give it a small nudge,” she mentioned. “It’s going to deflect its path around the larger asteroid.”

“It’s only going to be a change of about one percent in that orbital period,” Chabot mentioned, “so what was 11 hours and 55 minutes before might be like 11 hours and 45 minutes.”

The check is designed to assist scientists perceive how a lot momentum is required to deflect an asteroid within the occasion one is headed in the direction of Earth one day.

“We are targeting to be as nearly head on as possible to cause the biggest deflection,” Chabot mentioned.

The quantity of deflection will rely to a sure extent on the composition of Dimorphos and scientists usually are not fully sure how porous the asteroid is.

Dimorphos is the most typical kind of asteroid in space and is a few 4.5 billion years outdated, Chabot mentioned.

“It’s like ordinary chondrite meteorites,” she mentioned. “It’s a fine grain mixture of rock and metal together.”

Johnson, NASA’s Planetary Defense Officer, mentioned greater than 27,000 near-Earth asteroids have been catalogued however none at present pose a hazard to the planet.

An asteroid found in 1999 referred to as Bennu that’s 1,650 toes huge will cross inside half the gap of the Earth to the Moon within the yr 2135 however the chance of an affect is taken into account very slight.

© 2021 AFP