On Monday, September 26, 2022, NASA's Double Asteroid Redirection Test (DART) spacecraft purposely collided with Dimorphos, an asteroid moonlet in Didymos' double-asteroid system. This was the first planetary defense test in which a spaceship collision attempted to alter an asteroid's orbit.
Two days after DART's impact, astronomers Teddy Kareta (Lowell Observatory) and Matthew Knight (US Naval Academy) captured the vast plume of dust and debris blasted from the asteroid's surface with the 4.1-meter Southern Astrophysical Research (SOAR) Telescope at NSF's NOIRLab's Cerro Tololo Inter-American Observatory in Chile. The dust trail or ejecta pushed out by the sun's radiation pressure, can be seen reaching from the center to the right-hand edge of the field of view in this new image, which at SOAR is about 3.1 arcminutes utilizing the Goodman High Throughput Spectrograph.
That would amount to at least 10,000 kilometers (6,000 miles) from the location of impact at Didymos' distance from Earth at the time of the observation.
According to Kareta, "it's incredible how clearly we were able to capture the structure and extent of the aftermath in the days following the impact."
Knight stated, "The DART team's next phase of work begins now as they analyze their data and observations by our team and other observers around the world who participated in studying this exciting event." In the following weeks and months, we want to employ SOAR to monitor the ejecta. The combination of SOAR and AEON is exactly what we need to keep track of changing events like this one.
These observations will help scientists learn more about the nature of Dimorphos' surface, such as how much material was ejected by the collision, how quickly it was ejected, and the distribution of particle sizes in the expanding dust cloud, such as whether the impact caused the moonlet to throw off large chunks of material or mostly fine dust. Analyzing this data may help scientists safeguard Earth and its people by better understanding the volume and composition of ejecta produced by an impact, as well as how this may affect an asteroid's orbit.
SOAR's observations highlight AURA's capability in planetary-defense planning and activities. The Vera C. Rubin Observatory, which is presently under construction in Chile, will undertake a census of the solar system in the future to look for potentially harmful asteroids. Didymos was found in 1996 using the UArizona 0.9-meter Spacewatch Telescope at Kitt Peak National Observatory, an initiative of the National Science Foundation's NOIRLab.