Scientists began to learn iron and surprising information about asteroids, after the launch of image analysis of the test of NASA’s Dart spacecraft, when it collided with the asteroid “Demorphos”, and the scientists found that when hitting it, the asteroids interact strangely like water, and not masses of gravel as they are, according to RT website.
And Dr. Phil Metzger, a planetary scientist at the University of Central Florida, posted on the social networking site “Twitter”: “I was shocked by the amount of projectiles.” , as shown in an image taken by a small Italian spacecraft near the asteroid at the time of the collision.
This image shows spider-like strands of material being expelled from Demorphos in the moments after the impact, but, Dr. Metzger said, experiments on Earth using sand or gravel and steel balls showed uniform, cone-shaped patches of material after the impact.
Understanding why Demorphos projectiles interact so differently from lab experiments may be important to the goals of the Dart mission, which seeks to understand whether a spacecraft’s similar effect can be used to deflect a dangerous asteroid away from Earth.
At the same time, it may reveal that the forces affecting a high-energy collision with an asteroid are similar to those that helped our planet to form in the early solar system, and “Demorphos” is not the first asteroid reached by humans, nor is it the first asteroid to generate more liquid-like mist at collision.
In 2019, the Japanese mission Hayabusa 2 used an impact instrument to sample some of the asteroid Ryugu material, which was then returned to Earth for study in late 2020. Images of the asteroid’s “balls” show the same ejecta material seen in the new images of the impact. Dart, according to Dr. Metzger.
Dr. Metzger pointed out that ejected materials can form when an object falls into the water, because water has strong surface tension forces (the force acting perpendicularly along the line of action of the unit of force when this force is parallel to the surface).
He continued, “But granular materials do not have any effect such as the strong surface tension of water, yes, there is cohesion between the particles, but it is very weak compared to the dynamics of the impact, and it is not able to regulate the projectiles of huge size.”
Dr. Metzger noted that it is possible for ejected materials to form when granular materials contain particles of sufficiently different sizes, and this occurs because the granular material, mainly small rocks, bounces into each other, and loses energy with each bounce, as does a ball bouncing off a surface Earth, meaning that when enough pebbles bounce back in space’s microgravity, some tend to condense into a region of space because interactions between individual rocks deprive them of the energy needed to travel further.
Dr. Metzger explained that this process, known as “granular collapse”, has been investigated in microgravity experiments, and is believed to be part of the process of forming planets and asteroids from the raw material of the protoplanetary disk around the Sun billions of years ago.
Dr. Metzger concluded that these findings highlight the importance of conducting actual experiments in space, “because we never know what we will see. The universe is amazing and complex.”