Spacecraft hit Dimorphos in planetary defence test, shortened space rock's orbit time by 32 minutes
A spacecraft intentionally crashed by the National Aeronautics and Space Administration (NASA) into an asteroid successfully deflected the orbit of the 160-metre space rock.
NASA’s Double Asteroid Redirection Test (DART) intentionally crashed a refrigerator-sized spacecraft into Dimorphos, a small moon orbiting the near-Earth asteroid called Didymos September 26, 2022.
The mission was to evaluate whether the impact could deflect this near-earth object from its orbit, potentially paving the way for a technology that could help protect Earth from future hazardous asteroid collisions.
Before the impact, Dimorphos took 11 hours and 55 minutes to orbit Didymos. The time has now been reduced to 11 hours and 23 minutes, NASA announced.
Read more: In a world first, NASA’s DART mission is about to smash into an asteroid. What will we learn?
“For the first time, humanity has changed the orbit of a planetary body,” Lori Glaze, director of NASA’s Science Mission Directorate’s Planetary Science Division, said at a press briefing October 11, 2022.
Scientists used ground-based telescopes to confirm that the spacecraft shortened Dimorphos’ orbit time by 32 minutes, according to the space agency.
NASA had earlier used models to estimate the impact would result in a change “between a few minutes and several tens of minutes”.
“The result of the 32-minute change is consistent with our estimates beforehand, but clearly at the upper end of that range,” Glaze said.
The mission was expected to be a huge success if it shortened the orbit by 10 minutes, NASA Administrator Bill Nelson said at the press briefing.
Experts will continue studying the aftermath of the impact. NASA said it was analysing the “ejecta” comprising asteroidal rock hurled into space post-impact.
The recoil from the blast, it added, substantially enhanced the spacecraft’s push against Dimorphos.
To gain more insights, the experts will gather more information on the asteroid’s physical properties, such as the characteristics of its surface and whether it is strong or weak.
“DART has given us some fascinating data about both asteroid properties and the effectiveness of a kinetic impactor [sending a spacecraft to defect an asteroid] as a planetary defense technology,” said Nancy Chabot, the DART coordination lead from the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland.
With new data, astronomers can better assess how effective a mission like DART is in helping protect Earth from a potential future asteroid collision, Glaze said.
Read more: Always look up: Earth’s top 7 asteroid defences
Previously, Southern Astrophysical Research (SOAR) telescope located in Cerro Pachón in Chile captured the vast plume of dust and debris from the asteroid’s surface after the impact.
The dust trail has been pushed away by the Sun’s radiation pressure, a press note read.
Hubble and James Webb telescopes observed the impact location before and after the impact. Images from James Webb showed plumes of material streaming away from the centre of the collision.
This powerful telescope will also be used to provide details of the asteroid’s composition. Hubble’s images captured the ejecta, which looked like rays stretching from the asteroid’s body.
The brightness of Didymos in the aftermath increased by three times, staying stead for eight hours, images from the telescope showed.
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