Planetary defense works: NASA’s DART probe successfully hit asteroid Dimorphos
After 10 months of flight in space, NASA‘s DART probe – the world’s first demonstration of planetary defense technology – successfully hit its target, the asteroid Dimorphos.
The flight control center at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, announced the successful collision at 7:14 p.m. ET (02:14 a.m. Kyiv time).
As part of NASA’s overall planetary defense strategy, DART’s encounter with asteroid Dimorphos demonstrates a viable technique for protecting the planet from an approaching Earth asteroid or comet, should one be detected.
“At its core, DART represents an unprecedented success for planetary defense, but it is also a mission of unity with a real benefit for all humanity,” said NASA Administrator Bill Nelson. “As NASA studies the cosmos and our home planet, we’re also working to protect that home, and this international collaboration turned science fiction into science fact, demonstrating one way to protect Earth.”
DART targeted the asteroid moon Dimorphos, a small body only 168 meters in diameter that orbits a larger (780 meters) asteroid called Didymos. None of the asteroids posed a threat to Earth.
The mission confirmed that NASA could successfully guide the spacecraft to deliberately collide with an asteroid to deflect it using a technique known as kinetic collision.
The research team will now observe Dimorphos with ground-based telescopes to confirm that the DART impact changed the asteroid’s orbit around Didymos. Researchers expect the impact to shorten Dimorphos’ orbit by about 1%, or about 10 minutes. Accurately measuring how much the asteroid has deflected is one of the main goals of the test.
“Planetary Defense is a globally unifying effort that affects everyone living on Earth,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. “Now we know we can aim a spacecraft with the precision needed to impact even a small body in space. Just a small change in its speed is all we need to make a significant difference in the path an asteroid travels.”
The spacecraft’s single instrument, the Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO), along with a sophisticated guidance, navigation, and control system that works in tandem with Small Body Real-Time Autonomous Navigation (SMART Nav) algorithms, enabled DART to identify and distinguish these two asteroids, targeting the smaller one.
These systems guided the 570-kilogram spacecraft through the final 90,000 kilometers of space toward Dimorphos, deliberately crashing into it at about 22,530 kilometers per hour to slightly slow the asteroid’s orbital speed. DRACO’s final images, taken seconds before impact, showed the surface of Dimorphos in close-up detail.
Fifteen days before the collision, DART, the Italian Lightweight CubeSat for Asteroid Imaging (LICIACube), provided by the Italian Space Agency, broke away from the spacecraft and took pictures of the collision of DART and the cloud of ejected material created by the impact of the asteroid. Together with the images obtained by DRACO, the LICIACube images should provide insight into the impact of the impact, helping researchers to better assess the effectiveness of the kinetic impact to deflect the asteroid. Since LICIACube does not have a large antenna, the images will be beamed back to Earth one after the other over the coming weeks.
In about four years, the European Space Agency’s Hera project will carry out detailed studies of Dimorphos and Didymos, paying particular attention to the crater left by the impact with DART and precisely measuring the mass of Dimorphos.