Incredible images show the aftermath of NASA’s asteroid deflection test
Incredible images of swirling dust clouds captured by NASAThe Double Asteroid Redirection Test (DART) spacecraft collided with an asteroid.
The refrigerator-sized spacecraft collided with a 520-foot-wide (160 m) space rock known as Dimorphos. September 26 last year.
The goal of the mission was to demonstrate that the technology could deflect asteroids that could pose a danger to Earth in the future.
This month, it turned out that DART shortened Dimorphos’ orbit by 33 minutes – almost five times more than predicted – and it was considered 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 stuck together over time.
The evolution of the debris cloud ejected from the collision of the DART spacecraft with Dimorphos. The first picture was taken just before the impact, and the last one almost a month later. The white arrow indicates the direction of the sun. The stripes in the background are the stars. The images were taken with the MUSE instrument on the Very Large Telescope.
The refrigerator-sized DART satellite collided with the 520-foot-wide (160 m) Dimorphos space rock on September 26 last year. The goal of the mission was to demonstrate that the technology could deflect asteroids that could pose a danger to Earth in the future.
“Asteroids are one of the most basic relics of what all the planets and moons in our solar system were made from,” said graduate student Brian Murphy.
The cloud of dust left after DART crashed into Dimorphos at 14,000 miles per hour (22,000 km/h) can tell us what happened when our solar system formed.
It could also provide more information about the chemical composition of these asteroids.
Astronomer Dr. Cyriel Opithom added: “Collisions between asteroids happen naturally, but you never know about it in advance.
“DART is a really great opportunity to study controlled exposure, almost like in a lab.”
The team used the European Southern Observatory’s Very Large Telescope (VLT) to monitor the DART mission as it passed seven million miles (11 million km) away.
For his research, published in Astronomy and astrophysicsthey observed the resulting debris for a month using the Multi Unit Spectroscopic Explorer (MUSE) instrument at the VLT station in Chile.
They found that immediately after the collision, the dust took on a blue color, indicating that it consisted of very small particles.
But over time, the particles began to gather together and form clumps, spirals and a long tail that escapes from solar radiation.
The tail and spirals appeared redder than the original dust cloud, suggesting that they are composed of larger particles.
MUSE also allowed scientists to study the chemical composition of Dimorphos from the dust it emitted.
This is because certain wavelengths of sunlight are reflected by certain molecules such as water (H₂O) and oxygen (O₂), allowing them to be identified.
This artist’s illustration shows the ejection of a cloud of debris following the collision of NASA’s DART spacecraft with the asteroid Dimorphos.
These two molecules, in particular, indicate the presence of ice inside the asteroidhowever, none could be found.
“Asteroids are not expected to contain significant amounts of ice, so finding any traces of water would be a real surprise,” said Dr. Opitome.
They also looked for traces of fuel from the DART spacecraft, but found none.
Dr. Opithom added: “We knew it was a long journey, as the amount of gas left in the tanks from the propulsion system would not have been huge.
“Moreover, by the time we started observing, some of them would have gone too far to be detected by MUSE.”
These researchers found that immediately after the collision, the dust ejected by Dimorphos had a blue color, indicating that it consisted of very small particles.
The light reflected from the surface of Dimorphos (pictured) became less polarized, and therefore more randomly oriented, immediately after the collision. The researchers suggest that this is due to the discovery of pristine material with a more symmetrical molecular structure that is less polarizing.
Another team from the Armagh Observatory and Planetarium used a different VLT instrument to study how the impact affected the asteroid’s surface.
When objects in space reflect sunlight, it partially polarizes it, meaning that the waves change from oscillating in many different directions to just one direction.
For his research, published in Letters from an astrophysical journalThe researchers used the FOcal Reducer/Low Dispersion Spectrograph 2 (FORS2) to observe the polarization of light reflected by Dimorphos.
“Tracking how the polarization changes depending on the orientation of the asteroid relative to us and the Sun allows us to reveal the structure and composition of its surface,” said study author Dr. Stefano Bagnulo.
They found that the light reflected from the asteroid’s surface immediately after the collision became less polarized and more randomly oriented.
They suggest that this is due to the discovery of pristine material with a more symmetrical molecular structure that is less polarized.
The asteroid also reflected more light after the impact, suggesting that this inner material is smoother than the rough exterior.
The fact that the inner part has a smoother texture and more regular molecular structure than the outer part can be explained by the fact that it was not exposed to the solar wind and radiation.
Another possibility is that DART completely destroyed the top layer of dimorphos, resulting in the formation 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 study took advantage of a unique opportunity when NASA hit an asteroid, so it cannot be repeated in any future.
“This makes the data obtained by the VLT during the collision extremely valuable when it comes to better understanding the nature of asteroids.”