Incredible images show the aftermath of NASA’s asteroid deflection test

Incredible images of the swirling dust clouds created when NASA’s DART (Double Asteroid Redirection Test) spacecraft hits an asteroid have been revealed.

The refrigerator-sized spacecraft collided with the 160m-wide space rock Dimorphos on September 26 last year.

The goal of the mission was to demonstrate that the technology can deflect asteroids that could pose a threat to Earth in the future.

It was revealed this month that DART has shortened Dimorphos’ orbit by 33 minutes – almost five times more than predicted – and has been deemed a success.

Scientists from the University of Edinburgh studied the aftermath of the collision, including what was in the debris it left behind and how it piled up over time.

“Asteroids are some of the most fundamental relics of what formed all the planets and moons in our solar system,” said graduate student Brian Murphy.

The cloud of dust left behind after DART sped into Dimorphos at 14,000 mph (22,000 km/h) can tell us what happened as our solar system formed.

It could also provide more information about the chemical composition of these asteroids.

The astronomer Dr. Cyrielle Opitom added: “Impacts between asteroids happen, of course, but you never know in advance.

“DART is a really great opportunity to study controlled impact almost like in a laboratory.”

The team used the European Southern Observatory’s Very Large Telescope (VLT) to observe the DART mission as it took place seven million miles (11 million kilometers) away.

For their study, published in Astronomy & Astrophysics, they observed the resulting debris for a month using the Multi Unit Spectroscopic Explorer (MUSE) instrument at the VLT in Chile.

They found that the dust was blue in color immediately after the collision, indicating it was made up of very fine particles.

But over time, the particles began to cluster together, forming clumps, spirals, and a long tail that stretched away from the sun’s radiation.

The tail and spirals appeared redder than the original dust cloud, suggesting they were composed of larger particles.

MUSE also allowed scientists to study the chemical makeup of Dimorphos from the dust it ejected.

This is because certain wavelengths of sunlight reflect off certain molecules, such as water (H₂O) and oxygen (O₂), allowing them to be identified.

These two molecules in particular would indicate the presence of ice inside the asteroid, but none could be found.

“Asteroids are not expected to contain appreciable amounts of ice, so finding traces of water would have been a real surprise,” said Dr. opitome.

They also looked for traces of propellant gas from the DART spacecraft, but that too could not be found.

dr Opitom added: “We knew it was a long road as the amount of gas that would remain in the tanks from the propulsion system wasn’t going to be huge.

“Also, some of it would have traveled too far to detect with MUSE when we started observing.”

Another team from the Armagh Observatory and Planetarium used another VLT instrument to study what the impact did to the asteroid’s surface.

When objects in space reflect sunlight, it becomes partially polarized, meaning the waves go from vibrating in many different directions to just one direction.

For their study, published in Astrophysical Journal Letters, the researchers used the FOcal Reducer/low dispersion Spectrograph 2 (FORS2) to observe the polarization of the light reflected from Dimorphos.

“Tracking how the polarization changes with the asteroid’s orientation relative to us and the Sun reveals the structure and composition of its surface,” said study author Dr. Stefano Bagnulo.

They found that immediately after the collision, the light reflected from the asteroid’s surface was less polarized and therefore more randomly oriented.

They suggest this is because it revealed pristine material with a more symmetrical molecular structure that is less polarizing.

The asteroid also reflected more light after impact, suggesting this inner material is smoother than the rough exterior.

The fact that the interior has a smoother texture and more regular molecular structure than the exterior may be due to this it had not been exposed to solar wind or radiation.

Another possibility is that DART completely destroyed the top layer of Dimorphos, resulting in the production of fine dust particles.

“We know that under certain circumstances, smaller fragments reflect light more efficiently and polarize it less efficiently,” said graduate student Zuri Gray.

dr Optiom added, “This research capitalized on a unique opportunity when NASA impacted an asteroid, so it cannot be duplicated by any future facility.”

“This makes the data obtained with the VLT around the time of impact extremely valuable in better understanding the nature of asteroids.”