Leonard David's INSIDE OUTER SPACE

Image credit: Illustration by John DiJulio, University of Virginia Communications

There’s some new planetary defense news – specific to nuking an Earth-threatening asteroid.

Experiments at CERN’s Super Proton Synchrotron (SPS) suggest that metal-rich asteroids are more resistant than previously assumed. The asteroid tests challenge nuclear-deflection models.

The European Organization for Nuclear Research is known as CERN.

There have been those advocates that, in the case of an impending collision with Earth, nuclear deflection may well be a last-resort option, leading to lots of fragments. However, a key uncertainty in such a mission would be the materials properties of the asteroid.

Credit: NASA/Don Davis

Scientific challenge

“Planetary defense represents a scientific challenge,” explains Karl-Georg Schlesinger, co-founder of the Outer Solar System Company (OuSoCo), a start-up developing advanced material-response models used to benchmark large-scale nuclear deflection simulations.

“The world must be able to execute a nuclear deflection mission with high confidence,” Schlesinger said, “yet cannot conduct a real-world test in advance. This places extraordinary demands on material and physics data.”

Stronger than expected – the Campo del Cielo meteorite. Image credit: E Halwax

Experimental campaign

To tackle that problem, an experimental campaign was carried out at CERN’s High Radiation to Materials facility (HiRadMat) in Switzerland. Researchers irradiated a Campo del Cielo iron meteorite sample with 440 GeV protons from CERN’s Super Proton Synchrotron.

Campo del Cielo refers to a group of iron meteorites that fell to Earth 4,200 to 4,700 years ago in Argentina where they were found.

The Campo del Cielo meteorite was exposed to 27 successive short, intense pulses of the SPS proton beam, reproducing impact-relevant shock conditions not attainable with conventional laboratory techniques.

Controlled lab conditions

“Our results demonstrate that asteroid materials can absorb significantly more energy without structural failure than normal material parameters would suggest. Crucially, we were able to reproduce–under controlled laboratory conditions–the discrepancy factor observed between laboratory-derived yield strength values and those inferred from atmospheric meteor breakup events,” notes a research paper – “Dynamical development of strength and stability of asteroid material under 440 GeV proton beam irradiation” – in Nature Communications.

CERN’s High Radiation to Materials facility (HiRadMat).
Image credit: CERN

“The material became stronger, exhibiting an increase in yield strength, and displayed a self-stabilizing damping behavior,” explains Melanie Bochmann of BoS GmbH, headquartered in Mörbisch am See in Austria and a co-founder and co-team lead alongside Schlesinger.

Unexplored possibilities

This research does imply that much larger amounts of energy can be deposited into asteroid material than previously assumed–without structural failure.

“This opens yet unexplored possibilities for nuclear energy-density asteroid deflection techniques, where deep energy coupling is desired without fragmentation,” the research paper states, with future work exploring this scenario in detail.

Image credit: NASA/JPL-Caltech

Next step

“In our first experimental campaign, we focused on a metal-rich asteroid material because its more homogeneous structure is easier to control and model, and it met all the safety requirements of the experimental facility,” Bochmann and Schlesinger explain in the CERN Courier. “This allowed us to collect, for the first time, non-destructive, real-time data on how such material responds to high-energy deposition.”

“As a next step, we plan to study more complex and rocky asteroid materials, the two researchers point out.

“One example is a class of meteorites called pallasites, which consist of a metal matrix similar to the meteorite material we have already studied, with up to centimeter-sized magnesium-rich crystals embedded inside. Because these objects are thought to originate from the core–mantle boundary of early planetesimals, such experiments could also provide valuable insights into planetary formation processes, Bochmann and Schlesinger state in the CERN Courier.

For more information, go to the research paper at:

https://www.nature.com/articles/s41467-025-66912-4