Skip to main content

Scientists observe the aftermath of a spacecraft crashing into asteroid

When NASA deliberately crashed a spacecraft into an asteroid last year, it wasn’t only a thrilling test of planetary defense. It was also a unique opportunity for scientists to observe an asteroid system and see the effects of the crash, letting them learn more about what asteroids are composed of. Earlier this month, images of the impact captured by the Hubble Space Telescope were released, and now we can see the impact from another view, captured by the European Southern Observatory’s Very Large Telescope (ESO’S VLT).

The Very Large Telescope is a ground-based set of four telescopes located in Chile, which were able to see the aftermath following the DART spacecraft impacting the asteroid Dimorphos. The images show the cloud of debris thrown up by the impact, called the ejecta, between the time just before the impact on 26 September 2022 all the way through to a month later on October 25. Through this time, the cloud developed clumps and spirals and settled into a long tail formed by radiation from the sun.

The evolution of the cloud of debris that was ejected when NASA’s DART spacecraft collided with the asteroid Dimorphos.
This series of images, taken with the MUSE instrument on ESO’s Very Large Telescope, shows the evolution of the cloud of debris that was ejected when NASA’s DART spacecraft collided with the asteroid Dimorphos. The first image was taken on 26 September 2022, just before the impact, and the last one was taken almost one month later on 25 October. Over this period several structures developed: clumps, spirals, and a long tail of dust pushed away by the Sun’s radiation. The white arrow in each panel marks the direction of the Sun. ESO/Opitom et al.

Studying this ejecta using spectroscopy allowed the researchers to see that the cloud did not contain oxygen or water. “Asteroids are not expected to contain significant amounts of ice, so detecting any trace of water would have been a real surprise,” said one of the researchers, Cyrielle Opitom, in a statement. Another thing the team searched for was propellant from the spacecraft, but they didn’t find that either. “We knew it was a long shot, as the amount of gas that would be left in the tanks from the propulsion system would not be huge,” Opitom said.

Another study looked at how the asteroid changed once the spacecraft impacted it, by looking at the way light bounced off it.

“When we observe the objects in our Solar System, we are looking at the sunlight that is scattered by their surface or by their atmosphere, which becomes partially polarised,” explained researcher Stefano Bagnulo. “Tracking how the polarisation changes with the orientation of the asteroid relative to us and the Sun reveals the structure and composition of its surface.”

The team found increased brightness and changes in polarization which suggests the impact could have scrapped away the asteroid’s dull, outer layers to expose brighter, untouched material beneath. Alternatively, it could be that the impact threw up small particles of debris rather than larger ones, which could also explain why they reflected more light.

Finally, the European Southern Observatory brought together data from the various studies along with images taken from the spacecraft’s camera before it crashed to create this glorious artist’s impression of the moment the spacecraft collided with the asteroid.

This artist’s illustration shows the ejection of a cloud of debris after NASA’s DART spacecraft collided with the asteroid Dimorphos.
This artist’s illustration shows the ejection of a cloud of debris after NASA’s DART spacecraft collided with the asteroid Dimorphos. The image was created with the help of the close-up photographs of Dimorphos that the DRACO camera on the DART spacecraft took right before the impact. ESO/M. Kornmesser

The research is published in two papers in Astronomy & Astrophysics and The Astrophysical Journal Letters.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
NASA cracks open its first sample from an asteroid, foiling two sticky screws
NASA’s OSIRIS-REx curation engineer, Neftali Hernandez, attaches one of the tools developed to help remove two final fasteners that prohibited complete disassembly of the TAGSAM (Touch-and-Go Sample Acquisition Mechanism) head that holds the remainder of material collected from asteroid Bennu. Engineers on the team, based at NASA’s Johnson Space Center in Houston, developed new tools that freed the fasteners on Jan. 10.

NASA returned its first sample of an asteroid to Earth last year, landing a sample collected from asteroid Bennu in the Utah desert in September. Researchers were able to extract 70 grams of material from the canister that had been carried back to Earth by the OSIRIS-REx spacecraft, making this the largest asteroid sample ever brought to Earth. The scientists involved knew there was more material inside the mechanism, but getting at it proved difficult -- until now, as NASA has announced it has now managed to open up the troublesome mechanism.

You might think it would be an easy job to unscrew a canister and dump out the material inside, but extraction was a lengthy and technical process. That's because the focus was on preserving as much of the precious sample as possible, trying not to let any of the particles get lost. The issue was with two of the 25 fasteners that held the sample inside the collection mechanism.  The mechanism is kept inside a glove box to prevent any loss, and there were only certain tools available that worked with the glove box. So when the fasteners wouldn't open with the tools they had, the team couldn't just go at them with any other tool.

Read more
See a festive cosmic chicken captured by the VLT Survey Telescope
The Running Chicken Nebula comprises several clouds, all of which we can see in this vast image from the VLT Survey Telescope (VST), hosted at ESO’s Paranal site. This 1.5-billion pixel image spans an area in the sky of about 25 full Moons. The clouds shown in wispy pink plumes are full of gas and dust, illuminated by the young and hot stars within them.

A new image from the VLT Survey Telescope shows a beautiful region called the Running Chicken Nebula, which makes for a striking festive scene. Located 6,500 light-years away, this region is full of bright young stars that sculpt the clouds of dust and gas around them to form complex structures.

The Running Chicken Nebula comprises several clouds, all of which we can see in this vast image from the VLT Survey Telescope (VST), hosted at European Southern Observatory’s Paranal site. This 1.5-billion-pixel image spans an area in the sky of about 25 full moons. The clouds shown in wispy pink plumes are full of gas and dust, and are illuminated by the young and hot stars within them. ESO/VPHAS+ team. Acknowledgement: CASU

Read more
Scientists disagree on how fast the universe is expanding, and new tech is making it worse
An artist's rendition of NASA's SPHEREx space mission.

A view of thousands of galaxies in the galaxy cluster MACS0416, combining data from the James Webb Space Telescope and the Hubble Space Telescope. NASA

Something very strange is going on in the universe. The science of cosmology, which studies the universe on a grand scale, is in a state of crisis. Over the last century, scientists have found mountains of evidence that the universe is expanding over time, as they observed that the further away from Earth a galaxy is, the faster it is moving away from us.

Read more