In the vacuum of space, there is darkness. There is light. And there are asteroids.
What started as a loud, fiery launch from Vandenberg Space Force Base on November 24, 2021, the DART (Double Asteroid Redirection Test) spacecraft purposely ended it’s life on September 26, 2022.
The little spacecraft had a one way ticket to Dimorphos, slamming itself into the asteroid at 14,000 miles per hour.
In Earth’s first ever planetary defense test mission, NASA and Johns Hopkins Applied Physics Laboratory (APL) were successful with what they set out to do.
They changed the trajectory of an asteroid using kinetic impact.
It’s not just a Hollywood movie script anymore.
Armageddon. Deep Impact. Don’t Look Up.
Hollywood has certainly tantalized our senses and our fears with movies about asteroids and comets hitting our planet: oil drillers saving the world, a bomb splitting a comet in two, ignoring the inevitable.
Could any of these scenarios become a reality?
On February 15, 2013, a meteor exploded over Chelyabinsk, Russia. The explosion created an airburst and shockwave that struck six cities across the country. That asteroid was only 60-feet wide but weighed 10,000 metric tons. Astronomers have estimated that there are tens of thousands of asteroids near our planet that are 500 feet wide and larger. These are big enough to completely destroy much of our planet if we were to take a direct hit.
How can we deflect an asteroid without further endangering our planet?
One of the core missions of the DART spacecraft was to test kinetic impact. Could a spacecraft the approximate size of a large van, weighing about 1,260 pounds and moving at 3.8 miles per second at impact move an asteroid that was about 530 feet wide?
Dimorphos was the perfect candidate to test this theory.
An asteroid orbiting another asteroid.
Asteroid Didymos and its small moonlet Dimorphos make up what’s called a binary asteroid system. This means the small moon Dimorphos orbits the larger body Didymos.
Neither Didymos nor Dimorphos would ever hit Earth, but their “close” proximity to Earth (and by close, I mean approximately 7 million miles) made them ideal candidates for testing kinetic impact.
NASA and APL wanted to see if DART would alter the Dimorphos’ orbit around Didymos.
Before impact, it took Dimorphos 11 hours and 55 minutes to orbit Didymos.
And then DART said hello to Didymos. And ultimately goodbye to us.
When DART hit Dimorphos, telescopes and cameras in space and on Earth were there to capture the impact.
And it was spectacular.
Did kinetic impact work?
The news we were all eagerly waiting to hear was recently announced at a NASA press conference.
Astronomers using telescopes on Earth have measured that DART’s impact altered Dimorphos’ orbit around Didymos by 32 minutes – shortening it from 11 hours and 55 minutes to 11 hours and 23 minutes. This surpassed NASA’s benchmark by more than 25 times.
The investigation doesn’t end there.
Scientists are focusing on measuring the efficiency of momentum transfer from DART’s 14,000 mile per hour collision with Dimorphos. They are analyzing the ejected material – that long plume of asteroidal rock displaced and launched into space by the impact. That recoil from the blast of debris enhanced DART’s push on Dimorphos. Scientists want to look at the asteroid’s physical properties, such as the character of its surface, especially how strong or weak it was.
This successful test and all of these observations will make a big difference next time….when we need to do this for real.