DART Data Proves Viability of Asteroid Deflection
New DART data in papers published by the University of Maryland shows the asteroid deflection mission would be a viable option for planetary defense.
"We can't stop hurricanes or earthquakes yet, but we ultimately learned that we can prevent an asteroid impact with sufficient time, warning and resources."
Derek Richardson, astronomy professor at UMD and a DART investigation working group lead.
In four papers published in the journal Nature on March 1, 2023, the DART team -- which includes University of Maryland astronomers -- detailed DART's successful impact, the possible physics behind the collision, observations of the resulting debris ejected from the asteroid and calculations of Dimorphos' orbital changes. The findings confirm the feasibility of redirecting near-Earth objects like asteroids as a planetary defense measure.
"We can't stop hurricanes or earthquakes yet, but we ultimately learned that we can prevent an asteroid impact with sufficient time, warning and resources," said Derek Richardson, a professor of astronomy at UMD and a DART investigation working group lead. "With sufficient time, a relatively small change in an asteroid's orbit would cause it to miss the Earth, preventing large-scale destruction from occurring on our planet."
Richardson and his UMD Department of Astronomy colleagues Professor Jessica Sunshine and Principal Research Scientist Tony Farnham played critical roles in studying the effectiveness of the DART mission to deflect an asteroid from an Earth-bound path.
Farnham was instrumental in computing the geometrical conditions and dimensions needed to interpret observations of the event accurately. Using data from spacecraft engineers and from the Didymos Reconnaissance and Asteroid Camera for Optical Navigation (DRACO), Farnham helped determine what the DART spacecraft was looking at as it approached Dimorphos.
DART Data Shows Ejecta Contributed to Trajectory Change
The DART data indicates that the spacecraft was not the sole provider of momentum in the impact with Dimorphos; an additional shove was caused by violent spews of debris when the spacecraft slammed into the diminutive asteroid moon.
"There was so much debris ejected from the impact that Dimorphos was pushed approximately 3.5 times more effectively compared to being hit by the DART spacecraft alone," explained Richardson, who helped compute and verify the momentum transferred between the DART spacecraft and Dimorphos.
The DART mission represents a major first step to developing appropriate planetary defense strategies against near-Earth objects like asteroids.
In a related story, NASA's Hubble Space Telescope captured a series of photos of asteroid Dimorphos when it was deliberately hit by the 1,200-pound DART spacecraft.
Hubble's time-lapse movie of the aftermath of DART's collision reveals surprising and remarkable, hour-by-hour changes as dust and chunks of debris were flung into space. Smashing head on into the asteroid at 13,000 miles per hour, the DART impactor blasted over 1,000 tons of dust and rock off of the asteroid.
The Hubble movie offers invaluable new clues into how the debris was dispersed into a complex pattern in the days following the impact. This was over a volume of space much larger than could be recorded by the LICIACube cubesat, which flew past the binary asteroid minutes after DART's impact.
(Source: Science Daily and NASA news releases. NASA images)