DART successfully impacts Dimorphos asteroid

Image courtesy of NASA

NASA's Double Asteroid Redirection Test (DART) successfully collided with the asteroid Dimorphos, moonlet of the larger Didymos asteroid today at 7:14 PM EDT. The event was broadcasted live on NASA's offical YouTube channel.

Created by the John Hopkins Applied Physics Laboratory (APL) for the purpose of testing planetary defense solutions against asteroids, DART is an unmanned spacecraft created with the intention of not only showcasing a method of defense against asteroids but allowing scientists to better prepare future solutions via the data gained from its impact as well as showcasing multiple new technologies.

Chief among these technologies is the Small-body Maneuvering Autonomous Real Time Navigation (SMART Nav) system which DART successfully tested on July 1 and August 2 with the help of Jupiter and its moon Europa. This system allows the craft to autonomously maneuver itself towards Dimorphos by feeding images taken by Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO) into a computer algorithm that analyzes the images and adjusts DART's course accordingly.

Also notable is the Italian Space Agency's (ASI) Light Italian Cubesat for Imaging of Asteroids (LICIACube) which was deployed by DART for the purpose of capturing and analyzing the effects of DART's impact.

Launched into space via a SpaceX Falcon 9 Block 5 rocket from Vandenberg Air Force Base, DART slammed into Dimorphos as it passed in front of Didymos at 14,000 mph, making it not only the first planetary defense mission in the history of mankind, but the first successful mission as well. Scientists are currently working on analyzing the data from the impact.

Update 9/29/22: Both the James Webb Space Telescope (JWST) and the Hubble Space Telescope (HST) were able to observe DART's impact on Dimorphos.

Image courtesy of NASA

JWST was able to capture an image of the asteroid before the impact as well as several more images over a period of five hours with its Near Infrared Camera (NIRCam), a feat which posed a significant challenge for Webb due to the speed of the asteroid. In order to track Dimorphos, Webb's team utilized a method they had tested in the upcoming weeks that allowed Webb to track asteroids at up to three times its original speed limit.

Scientists also hope to scan the area of impact with Webb's Mid-Infrared Instrument (MIRI) and Near Infrared Spectrograph (NIRSpec) in order to learn more about the asteroid's chemical composition.

Images courtesy of NASA

Hubble captured 45 images total over a several hour period as part of Cycle 29 General Observers Program 16674, showcasing Dimorphos immediately before and 15 minutes after the impact. Through these images, scientists estimate the brightness of the asteroid system increased as much three times normal after DART's collision and continue to remain so eight hours after.

Hubble plans to observe the Didymos-Dimorphos system 10 more times in the next three weeks for the purpose of determine the full scope of the effects of DART's impact on Dimorphos.

Update 10/11/22: Analysis of data has confirmed that DART's impact has succesfully altered the orbit of the Dimorphos, marking the first time mankind has successfully altered the orbit of a celestial object.

Graph courtesy of NASA

Before DART's impact, Dimorphos completed its orbit around its parent asteroid Didymos in 11 hours 55 minutes. After the impact, scientists estimate that a complete orbit now takes around 11 hours 23 minutes.

Scientists are now focused on gauging the efficiency of the momentum transfer from DART's 14,000 mile-per-hour collision with Dimorphos. To do so, data from DART's terminal approach and the LICIACube satellite observing the impact will be utilized to approximate the asteroid's shape and mass. The European Space Agency's (ESA) Hera probe will also conduct a scan of the area of impact in December 2026.