The dramatic mission to alter an asteroid’s trajectory left a trail of debris stretching tens of thousands of kilometers behind the “moon beast” Dimorphos, according to NASA.
Scientists say the “ejection” was largely created by the asteroid’s recoil after it was struck by a DART spacecraft in September.
“The investigative team considered the implications of how this planetary defense technique might be deployed. … This included further analysis of the ‘ejecta’ — the many tons of asteroid rock displaced by the impact and ejected into space,” NASA reported Dec. 15.
“Scientists estimate that the DART’s impact displaced over two million pounds (a million kilograms) of the dusty rock into space – enough to fill six or seven railroad cars,” NASA says. “Solar radiation pressure has stretched the ejection stream into a comet-like tail tens of thousands of kilometers long.”
NASA scientists continue to examine data and have not addressed the effects of the debris trail. However, the debris is not considered a threat to Earth.
The DART (Double Asteroid Redirection Test) mission was “the world’s first planetary defense technology demonstration.”
His goal was to see if a spacecraft could be used to change the path of a potentially dangerous asteroid should one threaten Earth.
From this perspective, it worked: DART’s 14,000-mph collision with Dimorphos slowed its rotation by 33 minutes, NASA says.
Dimorphos — a minor planet moon orbiting asteroid Didymos — posed no threat to Earth, making it a good test subject, experts say.
“Now we can begin to apply that knowledge,” Andy Rivkin, co-lead of the DART investigative team, said in the release. “Studying the ejecta from the kinetic impact, all of which originate from Dimorphos, is an important way to gain further insight into the nature of its surface.”
Calculations show that “the ejecta contributed more to the asteroid’s motion than the spacecraft,” says NASA.
Understanding this “transmission of momentum” will play a key role in developing a strategy to defend Earth from asteroids, NASA says.
The DART vehicle was built and operated by Johns Hopkins APL for NASA’s Planetary Defense Coordination Office, officials say.