On Thursday, the James Webb and Hubble telescopes revealed the first images of the Dart Mission, in which a spacecraft deliberately crashed into an asteroid. The incident also marked the first time the two most powerful space telescopes observed the same celestial object.
Hubble captured 45 images in the time immediately before and following DART’s impact with Dimorphos, the asteroid moonlet in the double-asteroid system of Didymos.
“This is an unprecedented view of an unprecedented event,” summarized Andy Rivkin, DART investigation team lead of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.
On September 26, DART intentionally crashed into Dimorphos. It was the world’s first kinetic impact mitigation technique test, using a spacecraft to deflect an asteroid that poses no threat to Earth and modifying the object’s orbit.
The historic test on space rock Dimorphos tests the Earth’s ability to defend itself against a potential future life-threatening asteroid.
Astronomers rejoiced as NASA’s Double Asteroid Redirection Test (DART) impactor slammed into its pyramid-sized target 11 million kilometres (6.8 million miles) from Earth on Monday night.
Images taken by Earth-bound telescopes showed a vast cloud of dust expanding out of Dimorphos and Didymos after the spacecraft hit.
An image taken by James Webb’s Near-Infrared Camera (NIRCam) four hours after impact shows “plumes of material appearing as wisps streaming away from the centre of where the impact took place”, according to a joint statement from the European Space Agency, James Webb and Hubble.
“Webb and Hubble show what we’ve always known to be true at NASA: We learn more when we work together,” said NASA Administrator Bill Nelson.
“For the first time, Webb and Hubble have simultaneously captured imagery from the same target in the cosmos: an asteroid impacted by a spacecraft after a seven-million-mile journey. All of humanity eagerly awaits the discoveries from Webb, Hubble, and our ground-based telescopes – about the DART mission and beyond,” he added.
James Webb’s images were shown in red because the telescope operates primarily in the infrared spectrum, which allows it to peer further into the universe.
The images from Hubble’s Wide Field Camera 3 were blue because it shows the impact on visible light.
Hubble images from 22 minutes, five hours and eight hours after impact show the expanding spray of matter from where DART hit on the asteroid’s left.
The accurate measure of DART’s success will be exactly how much it diverted the asteroid’s trajectory, so the world can start preparing to defend itself against more giant asteroids that could head our way.