[imagesource: ASI / NASA, via Associated Press]

There was no Ben Affleck. There was no Bruce Willis.

There were, however, wild scenes of celebration in the NASA control room as it became clear that the $330-million DART mission was going to be a smash hit.

If you’re playing catch-up, you should know that yesterday, roughly seven million miles from Earth, a NASA spacecraft crashed head-on into an asteroid.

It did so at a speed in excess of 22 000 kilometres per hour in the “first real-world test of humanity’s ability to nudge a threatening body off course before it could crash into Earth”.

CBS reports:

The asteroid in question, a 525-foot-wide body known as Dimorphos, is actually a moon orbiting a 2,500-foot-wide asteroid named Didymos. Neither poses any threat to Earth, either before or after the impact of NASA’s 1,260-pound Double Asteroid Redirection Test, or DART, spacecraft.

But the double-asteroid system offered an ideal target… becase the effects of the probe’s impact can be measured from Earth by precisely timing how the moonlet’s orbital period around Didymos changes as a result of the collision.

In the control room, scientists watched on as the spacecraft first locked onto its target and then went in for the kill.

Visuals showed the target slowly growing larger, as the final 1 600 kilometres was ticked off in under four minutes. At the time of impact, the spacecraft was travelling seven times faster than the bullet from an assault rifle.

For the moment of impact, you can start watching from around the one-minute-45-second mark:

That’s the sound of sweet relief at the end of years of planning and a 10-month voyage through space.

It’s been roughly 66 million years since a massive asteroid struck Earth and ended the reign of the dinosaur. This mission is the first step in ensuring we could avoid a similar fate.

We may as well point out some of the differences between this mission and what we saw in the likes of Armageddon and Deep Impact:

[Those films] imagined piloted flights carrying nuclear bombs to deflect or destroy their targets, [but] DART’s goal is much simpler and much less destructive.

While nuclear devices might be a last resort in some future armageddon-class scenario, deflection, not destruction, would still be the goal.

“You just don’t want to blow it up, because that doesn’t change the direction of all the material,” Lindley Johnson, NASA’s “planetary defense” officer, told CBS News before DART’s launch last November. “It’s still coming at you, it’s just buckshot instead of a rifle ball.”

Instead, you change the speed and direction ever so slightly.

Over time, that changes the position of the asteroid and its orbit and Earth lives to fight another day.

That’s if we haven’t made it all but uninhabitable before then.

[source:cbs]