The National Aeronautics and Space Administration (NASA) has confirmed that the spacecraft it crashed into asteroid Dimorphos last month successfully altered the asteroid’s orbit, marking the first time a human-built object changed the motion of a celestial body.
Scientists at the US space agency said the path of the 160m-wide (520ft) space rock was deflected when the DART probe hit it in September.
“Analysis of data obtained over the past 2 weeks by the #DARTMission team shows impact with Dimorphos has successfully altered the asteroid’s orbit by 32 minutes,” NASA said on Twitter.
CONFIRMED: Analysis of data obtained over the past 2 weeks by the #DARTMission team shows impact with Dimorphos has successfully altered the asteroid’s orbit by 32 minutes - marking the 1st time humans have changed the orbit of a celestial object in space! https://t.co/MjmUAFwVSO pic.twitter.com/4Qiy1mC4gK
— NASA Asteroid Watch (@AsteroidWatch) October 11, 2022
The aim of the $330 million proof-of-concept mission, which was seven years in development, was to test a potential strategy to defend the Earth against threatening objects. The success of the DART mission proves that such an idea would work if it is initiated early enough and the target is not overly massive.
"This mission shows that NASA is trying to be ready for whatever the Universe throws at us," NASA administrator Bill Nelson said in a statement.
The space agency released pictures from the Hubble Space Telescope and from a small Italian spacecraft placed 50km away from the impact to support its assessment.
On September 26, a refrigerator-sized NASA satellite carved a crater into Dimorphos, which sent debris out into space and created a cometlike trail of dust and rubble stretching several thousand kilometers. The impact took place some 11 million km from Earth.
The Double Asteroid Redirection Test (DART) spacecraft drove straight into the egg-shaped asteroid, which was roughly the size of a football stadium, at 22,000km/h (14,000mph), destroying itself in the process, BBC reported.
The asteroid orbits a much larger object called Didymos (780m wide; 2,550ft). Prior to the impact, the Dimorphos took 11 hours and 55 minutes to make one circuit of its sibling. After the impact, this orbital period was reduced by 32 minutes. The telescope evidence now indicates that the Dimorphos takes 11 hours and 23 minutes to complete one circuit. This means that Dimorphos has moved closer into to Didymos by "tens of metres".
The collision may have left Dimorphos "wobbling a bit", Reuters quoted NASA program scientist Tom Statler as saying. Although this may have an impact on the orbit, it will never go back to its original location, he said
