From Hollywood to reality: NASA’s planetary defence

Hollywood has churned out its fair share of storylines involving humankind heading out to deep space to neutralize a threat to Earth.

In the 1998 Bruce Willis and Ben Affleck blockbuster “Armageddon”, space shuttles are dispatched to blow up an asteroid with nuclear weapons.

In real life, things are way different and thankfully non-nuclear.

However, for scientists, the outcome is equally spectacular.

After a 10-month journey in space, NASA’s Double Asteroid Redirection Test (DART) – the world’s first planetary defense technology demonstration – successfully impacted its asteroid target on Monday, the agency’s first attempt to move an asteroid in space.

Benefit to humanity

Perhaps in ironic reference to the antics of Bruce Willis and Co., one of the NASA TV commentators called the success ‘a blockbuster’ moment.

Meanwhile, NASA Administrator Bill Nelson was only slightly more down to earth in his summation of the mission so far.

“This international collaboration turned science fiction into science fact, demonstrating one way to protect Earth,” he said, adding the mission is both an unprecedented success for planetary defense and one that brings unity and a real benefit for all humanity.

Meeting its target some 11 million kilometres from Earth, the DART spacecraft autonomously guided itself past the larger Didymos body (780-meters in diameter), the larger of two asteroids in a near-Earth asteroid system. It then collided with the smaller, orbiting Dimorphos asteroid (160-meters wide).

The aim was to nudge Dimorphos (which does not threaten Earth) off its regular orbit, demonstrating one method of asteroid deflection by changing its motion in space through kinetic impact.

In the coming days and weeks data and visuals from dozens of Earth-based telescopes as well as those in space, will confirm how much the space rock has been moved off its course.

Being ready 'for pretty bad day'

For B.C. based spaceflight historian and writer Chris Gainor, the importance of the mission cannot be overstated.

“It’s a real thing, it’s a real threat,” he told Kelowna10. “It may not be as immediate as hurricanes or earthquakes or things from climate change, but it’s still a real possibility. And it would be a pretty bad day if we weren’t ready for it.”

Gainor points to the massive impacts in Earth’s history such as the one that wiped out the dinosaurs, or far more recently, the 1908 Tunguska event when an asteroid exploded over Siberia and destroyed 80 million trees. Up to three people may also have been killed.

He said while DART and other missions are aimed at understanding the makeup of asteroids - are they piles of rubble or solid rocks - the most important thing is to figure out where potentially threatening ones are as early as possible.

“If you have a few years to prepare, just a very slight change in the velocity of an asteroid is all you’d need to do to protect the Earth.”

Movie goers in the late 1990s may have cheered at the dramatic climax to the Willis/Affleck flick but the reaction of the dozens of NASA mission specialists Monday was joyous.

Among those watching the extraordinary events was Lindley Johnson, NASA’s Planetary Defense Officer.

“DART’s success provides a significant addition to the essential toolbox we must have to protect Earth from a devastating impact by an asteroid,” he said.

Hollywood scriptwriters couldn’t have put it better.