Hubble captures an 'unexpected' twin tail produced by NASA's spacecraft asteroid impact

NASA's planetary defense test results show that we should be able to slam a spacecraft into a hypothetical hazardous asteroid as a means to alter its trajectory and prevent it from hitting Earth.

In an update on Twitter, NASA wrote that after the impact, "experts expected the ejecta to expand and fade in brightness as time went on after impact. However, the twin tails are a surprising development."

1/ *NEW* Hubble images taken after @NASA 's Double Asteroid Redirection Test (DART) mission reveal the Didymos-Dimorphos system now has two tails of dust, ejected from the impact on 27 September 2022 at 01:14 CEST. pic.twitter.com/F1k7YFxb31

— HUBBLE (@HUBBLE_space) October 20, 2022

“Repeated observations from Hubble over the last several weeks have allowed scientists to present a more complete picture of how the system’s debris cloud has evolved over time,” a separate statement from NASA and the European Space Agency reads.

“The observations show that the ejected material, or 'ejecta,' has expanded and faded in brightness as time went on after impact, largely as expected,” the statement continues. "The twin tail is an unexpected development, although similar behavior is commonly seen in comets and active asteroids. The Hubble observations provide the best-quality image of the double-tail to date."

More Didymos observations to come

Scientists will carry out more observations and analysis to better understand how the split tail formed, and whether it's relevant to DART's overall mission. NASA pointed out that the northernmost tail is the one that was newly created.

DART won't be the only mission to send a spacecraft to the Didymos asteroid system. In four years' time, the European Space Agency (ESA) plans to have three spacecraft — from a mission called Hera — carrying out follow-up investigations to cover all bases and investigate the long-term effects of the DART mission.

Hubble started capturing images of the Didymos asteroid system soon after the DART spacecraft crashed into its target. The space observatory has also captured images of the asteroid at the same time as the James Webb Space Telescope, marking the first time the observatories worked in tandem.

NASA's DART mission is another historic world first for a space agency that also recently flew the first off-world helicopter and extracted the first oxygen from Mars' atmosphere. The planetary defense DART mission was the first time a space mission intentionally altered the trajectory of an asteroid in space.