Spacecraft crashing into an asteroid at 15,000 km/h is not a complacent NASA experiment, writes TOM LEONARD

One day in late September, a box-shaped spacecraft weighing about half a ton will slam into an asteroid seven million miles from Earth at a speed of 15,000 mph, with the aim of propelling it into a new orbit.

This suicide mission by a golf-cart-sized craft isn’t just a self-indulgent experiment dreamed up by NASA scientists with money to burn.

The very future of humanity may hinge on its success, as the $330m (£269m) Double Asteroid Redirection Test (DART, for short) may well provide the answer to a problem that worries astronomers for centuries: what to do when an asteroid is on a collision course with our planet.

“This is a mission for planet Earth – all people on Earth – because we would all be at risk,” said NASA Administrator Bill Nelson, who added that Dart had “transformed science -fiction in scientific reality”.

The DART mission will reach its final phase later this year when the object reaches the asteroid Dimorphos

Since the 1980s, when scientists first realized the six-mile-wide Chicxulub crater off Mexico’s Yucatan Peninsula had been left behind by an asteroid whose impact triggered the massive destruction of all non-avian dinosaurs, Hollywood latched onto the blockbuster potential of such a storyline.

Movies like Armageddon, Deep Impact and, most recently, Don’t Look Up, have all made millions at the box office by playing on our fear of an extinction-level event triggered by a planet-killing asteroid.

And, according to NASA, these fears are not misplaced. He classified around 28,000 asteroids as “Near-Earth” objects and his scientists believe there could be thousands of them large enough to cause catastrophic damage if they hit Earth.

The approximately 200 impact craters that have so far been discovered around the world bear witness to the fact that the Earth has been shaken quite a bit by asteroids over the millennia.

Pictured is the SpaceX Falcon 9 rocket that carried DART off-planet when it launched in November 2021

Pictured is the SpaceX Falcon 9 rocket that carried DART off-planet when it launched in November 2021

The role of the DART mission is to test the effectiveness of an asteroid deflecting method involving a “kinetic impactor”, in this case a spacecraft moving at over four miles per second.

NASA hopes to establish that if you hit an asteroid or comet hard enough when it’s far enough away from Earth, you can knock it off course so it never hits us.

Launched in June of last year aboard one of Elon Musk’s SpaceX Falcon 9 rockets from an air base in California, Dart will target a tiny ‘moonlet’, or small moon, just 530 feet across. called Dimorphos, which orbits the largest asteroid Didymos, a Rock 2,560 feet in diameter.

Neither is on a collision course with Earth and they were chosen because even if Dimorphos is successfully hijacked, there is no risk of it approaching us.

Once in the Didymos system, it will hit the moon head-on, propelled by its electric propulsion system powered by 28-foot-long solar panels.

The more material from the asteroid that is crushed by Dimorphos through the impact, the more it will be moved out of its path.

Scientists expect the impact to send the smaller asteroid into a tighter orbit around the larger one. The spaceship, meanwhile, will be destroyed.

All of this will be recorded by a small Italian-made satellite carried by DART, which will be released a few days before the spacecraft hits the asteroid, so that it can record the aftermath of the collision.

During this time, an on-board camera will transmit images of the moment of impact.

Scientists will also be able to follow what is happening by telescope from Earth and, four years later, by another satellite, Hera, which is due to be launched in 2024 by the European Space Agency.

The spacecraft was powered by two Roll Out Solar Panels (ROSAs), which provide it with solar energy

The spacecraft was powered by two Roll Out Solar Panels (ROSAs), which provide it with solar energy

Finding a way to deal with an incoming asteroid makes a lot of sense because unlike other natural threats like earthquakes and volcanoes, we can see one coming years from now.

And experts generally think it’s a question of when, not if, Earth will have to face one next.

As we have seen, Hollywood realized long ago that asteroids deserved to be treated in a disaster movie.

Inevitably, the methods they devise to avert the imminent destruction of the world have been rather more dramatic than the DART.

In the 1998 film Armageddon, a team of deep-sea oil drillers led by Bruce Willis are sent into space to deal with a Texas-sized asteroid set to hit Earth – wiping out all life – in 18 days. .

An advanced version of the space shuttle lands them on the rock where they detonate a nuclear bomb, splitting the asteroid into two halves which both fly safely past the planet.

The plot isn’t entirely ridiculous – NASA actually trained astronauts on how they could actually land and walk on an asteroid, recreating the near-zero gravity conditions on the seabed off the coast of Florida. .

Possible scenarios that have been mooted for an asteroid landing could include a mission to collect rock samples – asteroids are known to sometimes contain rare elements – or to install rocket engines on its surface which could then be triggered to modify its trajectory.

But when it comes to exploding an asteroid, scientists believe that even if it were possible (and after eons spent in space they are extremely resilient), the gravitational pull of its core would actually force the rock to be reconstituted.

When it arrives at Dimoprhos, it will crash headfirst into the asteroid in an attempt to deflect its course.

When it arrives at Dimoprhos, it will crash headfirst into the asteroid in an attempt to deflect its course.

An alternative that scientists say might work would be to detonate a nuclear bomb or missile near the asteroid, but the use of nuclear weapons in space is prohibited by international law, so there is very little probable to test this risky thesis for the moment.

Another theory is that the gravity exerted by a nearby flying spacecraft – known as a “gravity tractor” – could be enough to nudge the asteroid onto a new course.

However, aside from the wisdom of risking it all on Bruce Willis, perhaps the main reason Armageddon was so unrealistic was its timeline.

According to Nancy Chabot, DART project scientist, a spacecraft could not be launched at the last minute to save the Earth.

“It’s something you do five, ten, 15, 20 years in advance – gently nudge the asteroid so it sails its way happily and doesn’t impact Earth,” she said. declared.

Dimorphos orbits a larger asteroid called Didymos and was chosen because even if something goes wrong, it is unlikely to be on a collision course with Earth.

Dimorphos orbits a larger asteroid called Didymos and was chosen because even if something goes wrong, it is unlikely to be on a collision course with Earth.

It’s good if you have enough warning.

While nearly all of the largest “near-Earth” asteroids have already been located and none of them are likely to hit us for at least the next century, of the estimated 28,000 to be out there that are at least 460 feet wide, only 10,000 have been spotted.

And even the smallest of them is big enough to devastate a small American state.

Scientists continually photograph space in search of new asteroids, using computers to detect any signs of movement, such as when something passes in front of a distant star.

However, smaller asteroids glow more dimly and must approach quite close to Earth before they are noticed.

A mountain-sized asteroid known as 1998 OR2 passed Earth in what NASA called a “close approach” – in fact, 3.9 million kilometers away – two years ago.

Future plans could see astronauts landing on asteroids themselves to collect rock samples or attempting to deflect their course by mounting rocket engines on the objects

Future plans could see astronauts landing on asteroids themselves to collect rock samples or attempting to deflect their course by mounting rocket engines on the objects

In 1999, the space-watching world was horrified when a “city killer” asteroid up to 427 feet across came within 45,000 miles of Earth, or less than one-fifth of the distance to the Moon.

Michael Brown, an Australian astronomer, said it “would have exploded like a really big nuclear weapon” if it hit the planet.

Smaller space rocks – called meteors – typically burn up in Earth’s atmosphere, visible as shooting stars.

In 2013, a previously undetected meteor about 20 meters across shattered above the Russian city of Chelyabinsk, releasing up to 30 times more energy than the Hiroshima atomic bomb.

Some scientists say it briefly burned so violently that it was brighter than the Sun.

Earth has not been hit by a large meteor since the Tunguska event of 1908, when a meteor estimated to be up to 250 feet in diameter fortunately landed in an uninhabited region of Siberia.

It destroyed 80 million trees and left charred reindeer carcasses in an area twice the size of Los Angeles.

If he had arrived four hours later, he would have destroyed St. Petersburg.

Each year, June 30, the anniversary of the Siberia Incident, is marked as Asteroid Day.

Its co-founders – including the late Stephen Hawking and Queen guitarist and astrophysicist Brian May – aim to raise awareness of the threat from asteroids and what can be done to protect the Earth.

A small spacecraft called DART could give a nudge in the right direction.

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