The impact of the DART probe against an asteroid seen from the Webb and Hubble telescopes

Among the millions of observers who witnessed the intentional collision of NASA’s DART probe with the Dimorphic asteroid were two notable: the James Webb Space Telescope and the Hubble Space Telescope. For the first time, these two large observatories simultaneously captured the same celestial target, which is a milestone for the researchers, who with these new data will be able to learn more about the nature of the asteroid’s surface, the amount of material that was ejected by the collision and how quickly it ejected. Additionally, Webb and Hubble captured the impact in different wavelengths of light: the first in infrared and the second in visible light. This detail will help determine if the crash threw up a lot of large chunks or mostly fine dust.

Combining this information, along with observations from ground-based telescopes, will help understand how effectively a kinetic impact like the one DART made can change an asteroid’s orbit. “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 images of the same target in the cosmos: an asteroid that was hit by a spacecraft. All of humanity eagerly awaits the discoveries to come from Webb, Hubble and our ground-based telescopes on the DART mission, and beyond.”

As explained by NASA in a statement, “Webb observed the impact location before the collision occurred, and then for several hours afterward. He worked for five hours, in total, and got 10 images. in Their Near Infrared Camera (NIRCam) show a tight, compact core, with columns of material appearing as pixels moving away from the center of where the impact took place.” Put like that it sounds simple, but for the US agency’s flight, planning and science teams it was quite a challenge, as DART was moving much faster than the original speed limit set for Webb. Hence they had to prepare for the event for weeks.

Scientists also plan to observe the asteroid system in the coming months using the Webb Mid-Infrared Instrument (MIRI) and the Webb Near Infrared Spectrograph (NIRSpec). The spectroscopic data will provide information on the chemical composition of the asteroid.

Images captured by the Hubble telescope at 22 minutes, 5 hours and 8 hours after impact. /

POT

For its part, Hubble also captured observations of the binary system before the impact, and also 15 minutes after DART collided with Dimorph. They extend from the body of the asteroid outwards. It is the material ejected from the shock. What has surprised astronomers is that some of the rays appear to be slightly curved, for which they still have no explanation.

Hubble will monitor the Didymos-Dimorphos system ten more times over the next three weeks. These periodic observations as the impact debris cloud expands and fades will paint a more complete picture of this phenomenon.