NASA successfully rammed the DART spacecraft directly into an asteroid this Monday, in a major first for planetary defense strategy (a move predicted in sci-fi movies like Meteor or Don’t Look Up). Yes, it was supposed to crash as hard as possible.

It’s a high point of a NASA project officially called the Double Asteroid Redirection Test, or DART, starting about $300 million and 7 years ago. The craft launched into space in Nov. 2021 from Vandenberg Space Force Base in California, on a one-way mission to test the viability of kinetic impact: Can NASA navigate a spacecraft to hit an asteroid and deflect it to a new course?

Monday’s test suggests the answer is yes.

An artist’s impression of what the DART spacecraft looks as it approached Dimorphus.

The real Dimorphus, taken through DART’s forward camera. Note that this asteroid looks pretty much like other asteroids we’ve sent probes to look at. Dimorphus isn’t a single rock so much as it is a rather largish gravel yard flying in loose formation. Only the cumulative gravitation from all its bits of rock and dust hold it together.

4 km wide Steinheim crater, now a small town called Steinheim am Albuch, located in Germany.

Scientists chose the Didymos (“twin”) binary system 7 million miles away from the Earth. The asteroid selected for the test poses no actual threat to Earth. It’s a large asteroid orbited by a smaller moonlet named Dimorphos. The system is readily observerable by several Earth-based telescopes, and the predicable orbit makes any deflection by DART easier to measure. The asteroid moonlet is a small body just 530 feet in diameter, about the size of the object that caused Steinheim crater 15 million years ago.

Earth is perpetually bombarded with debris from outer space. Luckily for us, most objects burns up during entry through our atmosphere, and we enjoy a bright trail in the night sky in the form of meteor showers. 

But on occasion, an object is so big it survives its entry through the atmosphere and leaves its mark on the planet, literally. They can be micrometeoroids small as a grain of sand. Or they can be 10 Km wide monsters like the Chicxulub impactor that wiped out the dinosaurs 65 million years ago. This we want to avoid.

An artist’s impression of the Chicxulub event that created the mass extinction event separating the Cretaceous and Paleocene eras. Pretty much every dinosaur that didn’t have wings died out as a result of this event. The crater it made today lies under the Yucatan Peninsula in Mexico just offshore, and is a little over six miles in diameter.

The Planetary Defense Coordination Office (PDCO) was created in 2016 as a planetary defense organization within NASA’s Planetary Science Division of the Science Mission Directorate. Their mission is to find, catalog, and develop techniques to stop or mitigate space impactors. The DART is their first mission.

The DART mission is managed by the John Hopkins University Applied Physics Laboratory (JHUAPL), with scientists and engineers from around the world contributing. The craft is about the size and weight of a large refrigerator. It was launched on a SpaceX Falcon 9 and powered by solar panels.

DART deliberately impacted the moonlet Dimorphos at speeds close to 15,00 mph (24,000 kph). Researchers expect DART’s impact to shorten Dimorphos’ orbit around Didymos by about 1%, or 10 minutes per orbit. Investigators will now observe Dimorphos using ground-based telescopes to track the exact trajectory. Like the image showing the explosive impact at top of page.

The Italian Space Agency’s CubeSat for Imaging of Asteroids was deployed from the DART spacecraft two weeks in advance in order to capture images of DART’s impact from nearby. We’ll see more of these images in the coming weeks.

That’s the asteroid Dimorphos in the center. It’s orbiting its parent asteroid, Didymus, shown at right. This is the DART spacecraft’s forward view as it flies at close to 15,000 miles per hour (24,000 kph) straight at its unsuspecting target.

NASA is also developing a new space telescope sentinel called the Near-Earth Object Surveyor specifically designed to seek out hazardous asteroids in the solar system. That mission could launch by 2026.


David Raiklen
David Raiklen

David Raiklen wrote, directed and scored his first film at age 9. He began studying keyboard and composing at age 5. He attended, then taught at UCLA, USC and CalArts. Among his teachers are John Williams and Mel Powel.
He has worked for Fox, Disney and Sprint. David has received numerous awards for his work, including the 2004 American Music Center Award. Dr. Raiklen has composed music and sound design for theater (Death and the Maiden), dance (Russian Ballet), television (Sing Me a Story), cell phone (Spacey Movie), museums (Museum of Tolerance), concert (Violin Sonata ), and film (Appalachian Trail).
His compositions have been performed at the Hollywood Bowl and the first Disney Hall. David Raiken is also host of a successful radio program, Classical Fan Club.