The James Webb and Hubble telescopes on Thursday showed their first images of a spacecraft that intentionally crashed into an asteroid, marking the first time the two most powerful space telescopes observed the same celestial object.
The world’s telescopes turned their gaze to the space rock Dimorphos earlier this week in a historic test of Earth’s ability to defend itself against a potentially life-threatening asteroid.
Astronomers rejoiced when NASA’s Double Asteroid Redirection Test (DART) impactor slammed into its pyramid-shaped target 11 million kilometers from Earth on Monday evening.
Images taken by ground-based telescopes showed a huge cloud of dust expanding out of Dimorphos – and its big brother Didymos, which it orbits – after the spacecraft was hit.
While these images showed matter spraying thousands of kilometers away, “the James Webb and Hubble images zoom in much closer,” said Alan Fitzsimmons, an astronomer at Queen’s University Belfast who has been involved in observations with the ATLAS project.
James Webb and Hubble can “see just a few miles from the asteroids and you can really clearly see the material flying away from that explosive impact from DART,” Fitzsimmons told AFP.
“It’s really quite spectacular,” he said.
Observations from the space telescopes will help reveal how much – and how fast – matter is being sprayed from the asteroid, as well as the nature of its surface.
– ‘A beautiful demonstration’ –
An image taken four hours after the impact by James Webb’s near-infrared camera (NIRCam) shows “clouds of material appearing as wisps streaming away from the center of the impact,” according to a joint statement from the European Space Agency. Webb and Hubble.
James Webb’s images are shown in red because the telescope operates primarily in the infrared spectrum, allowing it to see further into the universe than ever before.
The images from Hubble’s Wide Field Camera 3 were blue because they show the effect on visible light.
Hubble images from 22 minutes, five hours and eight hours after impact show the expanding nebula of matter from where DART impacted the asteroid’s left side.
The true measure of DART’s success will be exactly how much it deflected the asteroid’s trajectory so the world can prepare to defend itself against larger asteroids that may be heading our way in the future.
However, it will take ground-based telescopes and radar days or even weeks to figure out exactly where Dimorphos is compared to where it would have been.
Measurements using that data will likely begin next week, Fitzsimmons said.
“The problem we have right now is that there’s still a lot of dust and debris around the asteroids,” he said.
“How quickly astronomers can make this measurement depends on how efficient DART was,” he added. The further the asteroid is off course, the easier it is to measure.
Since launching in December and releasing the first images in July, James Webb has taken the title of Hubble’s most powerful space telescope.
As astronomers queue up for precious time to look at the universe, the DART test is the first time both telescopes have observed the same event.
Fitzsimmons said the images are “a nice demonstration of the extra science you can get from using more than one telescope at a time.”