A giant asteroid impact is thought to be the probable cause of the mass extinction of the dinosaurs around 66 million years ago.
While there is no potential for asteroid damage on Earth at this time, it is still important to keep our defense systems in place to prevent catastrophic consequences such as impacts by diverting the asteroid’s path if detected.
With this aim, NASA The Double Asteroid Redirection Test (DART) mission, the world’s first planetary defense test mission, launched last November. DART is the first mission dedicated to investigating and demonstrating a single method for asteroid deflection by changing the motion of asteroids in space through kinetic collisions. In short, it will collide with the asteroid and deflect it from its orbit to provide valuable information for the development of such a planetary defense system.
The part of the group of asteroids that has survived since the formation of the solar system has undergone many of the impact, dynamic, and thermal events that shape the structure and characteristics of its orbit.
Due to the inability to recreate collision conditions in laboratory experiments, the observed system of low gravity and low force effects remains largely unexplored until now. Moreover, the very large time scale involved in crater growth (more than a few hours in the case of DART) did not allow to simulate this impact process numerically until now.
In a new study published in The Planetary Science Journal, researchers University of Bern And the PlanetS National Center for Competence in Research (NCCR) simulates this effect in a new way. Their results suggest that it may distort its target more seriously than previously thought.
“Studying this as-yet-ununderstood system is not only important in the context of future-threatening asteroid distortion, but is also needed to determine the age of asteroid macroforms and surface ages.” Small study.
Recently, the artificial impact experiment of the Hayabusa2 JAXA mission on the surface of the asteroid Ryugu created a crater about 14 meters in diameter. This unexpectedly large crater suggests that at least the asteroid’s near surface is largely controlled by its weak gravity rather than its strength.
This mission shows that the asteroid could have a very loose internal structure. These structures are connected to each other through the interaction of gravity and small cohesive forces. It looks like a pile of rubble.
But previous simulations of the DART mission effect assumed a solid internal presence asteroid Target Dimorphos.
“This could dramatically change the results of the DART and Dimorphos collision, which is scheduled to occur next September,” said study lead author Sabina Radukan of the Institute of Physics and the National Center for Efficiency in PlanetS Research.
Instead of leaving a relatively small crater on the asteroid 160 meters wide, a DART impact at a speed of about 24,000 km/h could completely destroy Demorphos. Asteroids could also bend more strongly, and larger amounts of material could be ejected from the collision than previously thought.
In a new approach that takes into account shock wave propagation, pressure, and subsequent material flow, the researchers were able for the first time to model the entire drilling process that results from impacts on small asteroids such as Demorphos.
For researchers of this approach, Sabina Raducan was awarded by the European Space Agency and by the Mayor of Nice at a workshop on the HERA DART follow-up mission.
In 2024, the European Space Agency ESA It will send a space probe to Dimorphos as part of the HERA space mission. The aim was to visually investigate the following effects of the DART probe.
According to the researchers, having a good understanding of the potential outcomes of the DART effect can help them get the most out of HERA’s work.
Our work on impact simulation adds important potential scenarios that require us to broaden our expectations in this regard. “This is not only highly relevant to the context of planetary defense, but also adds an important piece to the puzzle of our understanding of asteroids in general,” he said.
magazine reference
- Sabina d. Radokan and Martin Goetsi. Reshaping and reshaping asteroids on a global scale through small-scale impacts, with applications on the DART and Hera missions. Journal of Planetary ScienceVolume 3, Issue 6. DOI: 10.3847 / psg / ac67a7
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