For First Time, Hubble And JWST Watched The Same Event: NASA Spacecraft Slamming Into An Asteroid

Hubble and JWST, two of the greatest space observatories, both recorded the moment NASA's DART mission purposefully collided with an asteroid earlier this week. 

It is the first time that these two famous telescopes have been utilised to view the same astronomical target simultaneously, and their cooperative effort is already shedding light on the course of this historic journey.

In a first-of-its-kind planetary defence mission, an unmanned spacecraft collided with the asteroid moonlet Dimorphos on Monday. Dimorphos is a tiny body with a diameter of about 160 metres (530 feet) and circles the Didymos, a bigger asteroid measuring 780 metres (2,560 feet) in diameter.

The goal was to determine if it would be feasible to divert an asteroid away from Earth if that were to happen. The mission was an "exceptional success for planetary defence," according to NASA Administrator Bill Nelson.

Webb and Hubble Capture Detailed Views of DART Impact. Image Credit: NASA/ESA/CSA/STScI

The crash made a loud boom. The crash-landing produced a sizable burst of flying debris, known as ejecta, as seen in brand-new Hubble and JWST photographs, although the two were able to catch somewhat different features that will help the scientific investigation of this event.

Astronomers anticipate learning more about Dimorphos' surface from the pair's observations, as well as how much and how quickly material was expelled during the crash. They also want to know how the asteroid was harmed by the collision: did many large pieces fly off or was it primarily fine dust?

Prior to the collision, JWST made one asteroid observation; after the impact, it made numerous more. The telescope recorded debris wisps and material plumes flying away from the crash site using its Near-Infrared Camera (NIRCam).

On Monday night, Hubble was hard at work taking images of the impact before and after it occurred elsewhere in the Solar System. Images taken after the collision showed debris shooting from the impact site like rays emanating from the asteroid's body.

There is now no consensus as to why some of the beams seemed to become slightly bent while they were being emitted by the asteroid. Additionally, according to Hubble's findings, Didymos' brightness rose thrice after impact.

Dimorphos will be seen by Hubble at least ten more times over the following three weeks, much as JWST will continue to do.

However, this is just the first chapter. ESA's Hera mission is scheduled to launch in October 2024 to conduct a thorough post-impact survey of Dimorphos to investigate the effects of the first kinetic impact test of asteroid deflection. 

The project will also be the first attempt by humans to send a probe to a binary asteroid system. JWST will examine the asteroid's chemical makeup over the next months using the NIRSpec and the Mid-Infrared Instrument (MIRI).

Reference(s): NewScientist