Recent observations indicate that the DART mission had a surprising effect on its target

Double Asteroid Redirection Test was a NASA space mission aimed at testing a method of planetary defense against near-Earth objects. It was designed to assess how much a spacecraft impact deflects an asteroid through its transfer of momentum when hitting the asteroid head-on. DART is the first-ever space mission to demonstrate asteroid deflection by kinetic impactor. The spacecraft launched on a SpaceX Falcon 9 rocket out of Vandenberg Space Force Base in California.

DART's impact altered Dimorphos' orbital period, decreasing it by about 33 minutes. However, a group of researchers measured the orbital period about a month later and discovered that it had increased to 34 minutes—1 minute longer than the first measurements. Even though it was a single impact from DART, some force continued to slow the asteroid's orbit, and astronomers don't yet know what that mechanism might be.

DART's purpose was a test of how asteroids respond to impacts. When the first data following the impact was released, the change in orbital period was great news, since this type of kinetic impact is a planetary defense technique, where a spacecraft intentionally collides with a Potentially Hazardous Asteroid to alter its course. The data from DART is helping both NASA and ESA prepare for the possibility of having to redirect an asteroid away from an eventual impact with Earth.

"We know the initial experiment worked. Now we can start to apply this knowledge," said Andy Rivkin, DART investigation team co-lead at the Johns Hopkins Applied Physics Lab (APL), back in December 2022 when the first DART data was released.

DART weighed 610 kg (1,340 lb) and it crashed into Dimorphos at approximately 22,530 km/h (14,000 mph). DART excavated a crater on the Dimorphos' surface that ejected more than 900,000 kg (990 US tons) of debris into space. Data also indicated DART's impact into Dimorphos also changed the trajectory of the moonlet's parent asteroid, Didymos.

Scientists estimated DART's impact displaced over one million kilograms (two million pounds) of the dusty rock into space—or enough to fill six or seven railroad cars. The DART science team is continuing to analyze their data, as well as new information on the composition of the asteroid moonlet and the characteristics of the ejecta to learn just how much DART's initial hit moved the asteroid, and how much came from the recoil.

Edited by : www.linkedin.com/in/priyanka-v23

Credits : https://phys.org/news/2023-09-dart-impact.html