NASA's DART asteroid now has a massive comet-like tail after dramatic spacecraft crash

Last year, NASA and ESA astronomers teamed up for an exercise that simulated an hazardous asteroid scenario. They found that with current technologies, we would be defenseless and woefully unprepared if we detect a dangerous asteroid six months before it reached Earth.

The DART mission is one of several initiatives aimed at advancing technology and improving our planetary defense capabilities. Its target asteroid Dimorphos, part of the Didymos asteroid system, poses no threat to Earth, and was used as a stand-in for a hypothetical dangerous asteroid on a collision course with Earth.

Our last post was Monday's observations of the debris from the https://t.co/2JwWaIaAWd

— CFHT (@CFHTelescope) ) September 28, 2022

The impact event took place on Monday, September 26. Shortly afterward, the Italian space agency's cubsesat spacecraft, LICIACube, beamed back close-up images of the crash. Within two days, a tail was easily visible from ground-based telescopes on Earth.

Will NASA's DART mission be a success?

Astronomers Teddy Kareta from Arizona's Lowell Observatory and Matthew Knight of the US Naval Academy trained the Southern Astrophysical Research (SOAR) Telescope in Chile on Dimorphos on September 28. Thanks to those observations they calculated that Dimorphos' tail measures at least 6,000 miles (10,000 kilometers) in length.

“It is amazing how clearly we were able to capture the structure and extent of the aftermath in the days following the impact,” Kareta explained in a press statement.

“Now begins the next phase of work for the DART team as they analyze their data and observations by our team and other observers around the world who shared in studying this exciting event,” Knight added. "We plan to use SOAR to monitor the ejecta in the coming weeks and months."

The observations made over the next few weeks will help to determine whether NASA's DART mission was a success. Last week, Jonathan McDowell, an astronomer from the Harvard-Smithsonian Center for Astrophysics, pointed out how the main scientific work will be conducted from Earth now that NASA's spacecraft is obliterated.

"Now the work of the astronomers begins," McDowell tweeted. "Every 11 hours, Dimorphos goes behind Didymos as seen from Earth. By measuring that time of disappearance, we can accurately measure the orbital period of Dimorphos and see if it has changed due to the impact."

Astronomers will also keep an eye on that tail and will take follow-up observations to figure out how much of it is made of large chunks and how much is just dust coming off the asteroid. The more we know, the better we'll be able to avert hypothetical disaster in the form of a massive space rock headed for Earth.