A frame-by-frame showing how gravity causes asteroid fragments to reaccumulate in the hours following impact. Credit: Charles El Mir/Johns Hopkins University

Incoming asteroids may be harder to break than scientists previously thought, finds a Johns Hopkins study that used a new understanding of rock fracture and a new computer modeling method to simulate asteroid collisions.

The findings, to be published in the March 15 print issue of Icarus, can aid in the creation of asteroid impact and deflection strategies, increase understanding of solar system formation, and help design asteroid mining efforts.

Business plan for asteroid mining.
Credit: Joel Sercel/ICS Associates Inc. and TransAstra

Tonge-Ramesh model

This new work was led by El Mir, a recent PhD graduate from the Johns Hopkins University’s Department of Mechanical Engineering and his colleagues, K.T. Ramesh, director of the Hopkins Extreme Materials Institute and Derek Richardson, professor of astronomy at the University of Maryland.

The researchers entered the same scenario into a new computer model called the Tonge-Ramesh model, which accounts for the more detailed, smaller-scale processes that occur during an asteroid collision. Previous models did not properly account for the limited speed of cracks in the asteroids.

End result

“Our question was, how much energy does it take to actually destroy an asteroid and break it into pieces?” says El Mir.

The research team found that the end result of their impact work was not just a “rubble pile” – a collection of weak fragments loosely held together by gravity.

Instead, the impacted asteroid retained significant strength because it had not cracked completely, indicating that more energy would be needed to destroy asteroids.

Meanwhile, the damaged fragments were now redistributed over the large core, providing guidance to those who might want to mine asteroids during future space ventures.

Chelyabinsk sky rendering is a reconstruction of the asteroid that exploded over Chelyabinsk, Russia on Feb. 15, 2013. Scientific study of the airburst has provided information about the origin, trajectory and power of the explosion. This simulation of the Chelyabinsk meteor explosion by Mark Boslough was rendered by Brad Carvey using the CTH code on Sandia National Laboratories’ Red Sky supercomputer. Andrea Carvey composited the wireframe tail. Photo by Olga Kruglova.
Credit: Sandia National Laboratories.

 When the time comes

“We are impacted fairly often by small asteroids, such as in the Chelyabinsk event a few years ago,” says Ramesh in a Hopkins Extreme Materials Institute press release. The Institute is located in Baltimore, Maryland.

“It is only a matter of time before these questions go from being academic to defining our response to a major threat,” Ramesh adds. “We need to have a good idea of what we should do when that time comes – and scientific efforts like this one are critical to help us make those decisions.”

For a visual view of this new work, go to:

The first phase of a new asteroid collision model, which shows the processes that begin immediately after an asteroid is hit—processes that occur within fractions of a second.

https://www.youtube.com/watch?time_continue=7&v=Vt_xwQYafOY

The second phase of a new asteroid collision model, which shows the effect gravity has on the pieces that fly off an asteroid’s surface after impact. This phase occurs over many hours.

https://www.youtube.com/watch?time_continue=12&v=ZjBgljnCtWk

To access the Icarus paper — A new hybrid framework for simulating hypervelocity asteroid impacts and gravitational reaccumulation – go to:

https://www.sciencedirect.com/science/article/abs/pii/S001910351830349X

 

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