Travelling in the darkness of space, the Double Asteroid Redirection Test is ready to rendezvous with its target and on September 26 engineers will intentionally crash it into an asteroid to test a unique technology that could be employed if an asteroid is hurtling towards Earth.
The spacecraft will impact a known asteroid that is not a threat to Earth and will aim to slightly change the asteroid’s motion in a way that can be accurately measured using ground-based telescopes. The spacecraft will test the kinetic impact method that could be used in the future if the need arises.
The spacecraft is targeting the Didymos asteroid system, which comprises a pair of asteroids, and it’s a one-way trip, making the observation and the data beamed back even more critical for engineers to process.
Where will Dart crash?
The probe is targeting Dimorphos, a moonlet which is approximately 160 meters in diameter and orbits Didymos, which is approximately 780 meters in diameter. Nasa has said that since Dimorphos orbits Didymos at a much slower relative speed than the pair orbits the Sun, the result of DART’s kinetic impact within the binary system can be measured much more easily than a change in the orbit of a single asteroid around the Sun.
The near-Earth asteroid was originally discovered in 1996 by Joe Montani of the Spacewatch Project at the University of Arizona. The Didymos system is an eclipsing binary as viewed from Earth, meaning that Dimorphos passes in front of and behind Didymos as it orbits the larger asteroid as seen from Earth.
What is DART spacecraft?
Launched in November 2021, the DART mission will be the first-ever space probe to demonstrate asteroid deflection by a kinetic impactor. The probe will strike the asteroid at a speed of nearly 24,000 kilometers per hour, with hopes of slowing down the asteroid slightly and changing its course.
The mission has been built and is operated by the Johns Hopkins Applied Physics Laboratory (APL), under the direction of NASA’s Planetary Defense Coordination Office (PDCO).
The data from the crash can help scientists create mini-impacts in a lab and build sophisticated computer models based on those results.