NASA’s DART mission succeeds in changing path of asteroid

12 Oct 2022

An image of the Dimorphos asteroid, taken by the Hubble Space Telescope on 8 October 2022. Image: NASA/ESA/STScI/Hubble

NASA said this marks humanity’s first time purposely changing the motion of a celestial object and is a demonstration of asteroid deflection tech.

NASA has confirmed that its Double Asteroid Redirection Test (DART) managed to alter the orbit of an asteroid by smashing into it at high speed.

Last month, the DART spacecraft completed its 10-month journey when it successfully collided with the asteroid Dimorphos in humanity’s first planetary defence test.

The DART mission was an experiment to see if an asteroid’s path can be changed by crashing into it, using a technique known as kinetic impact.

Prior to this impact, NASA said it took Dimorphos 11 hours and 55 minutes to orbit its larger parent asteroid, Didymos. After the collision, an investigation team has confirmed that Dimorphos’ orbit has been reduced by roughly 32 minutes.

NASA said this marks humanity’s first time purposely changing the motion of a celestial object, along with the first full-scale demonstration of asteroid deflection technology.

“All of us have a responsibility to protect our home planet,” NASA administrator Bill Nelson said. “After all, it’s the only one we have. This is a watershed moment for planetary defence and all of humanity, demonstrating commitment from NASA’s exceptional team and partners from around the world.”

Before the impact, NASA said a minimum successful orbit change of Dimorphos would have been 73 seconds or more. The early data shows DART surpassed the minimum benchmark by more than 25 times.

The investigation team is still acquiring data with ground-based observatories around the world. NASA said the focus is shifting to measure the efficiency of momentum transfer from DART’s roughly 22,500kph collision with the asteroid.

This includes analysis of ‘ejecta’, which are the bits of asteroid rock displaced and launched into space from the impact. NASA said the recoil from this blast of debris substantially enhanced DART’s push against Dimorphos.

NASA planetary science division director Lori Glaze said the result marks “one important step” in understanding the full effect of the kinetic impact.

“As new data come in each day, astronomers will be able to better assess whether, and how, a mission like DART could be used in the future to help protect Earth from a collision with an asteroid if we ever discover one headed our way,” Glaze added.

Last month, the James Webb Space Telescope and the Hubble Space Telescope teamed up for the first time to capture the result of DART’s impact. Webb’s instruments are being used to learn more about the asteroid’s chemical composition, while Hubble is monitoring how the ejecta cloud expands and fades over time.

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Leigh Mc Gowran is a journalist with Silicon Republic