Scale-dependent measurements of meteorite strength: Implications for asteroid fragmentation

Abstract Measuring the strengths of asteroidalmaterials is important for developing mitigation strategies for potential Earth impactors and for understanding properties of in situ materials on asteroidsduring human and robotic exploration. Studies of asteroiddisruption and fragmentation have typically used the strengths determined from terrestrial analog materials, although questions have been raised regarding the suitability of these materials. The few published measurements of meteoritestrength are typically significantly greater than those estimated from the stratospheric breakup of meter-sized meteoroids. Given the paucity of relevant strength data, the scale-varying strength properties of meteoriticand asteroidalmaterials are poorly constrained. Based on our uniaxial failure studies of centimeter-sized cubes of a carbonaceous and ordinary chondrite, we develop the first Weibull failure distribution analysis of meteorites. This Weibull distribution projected to meter scales, overlaps the strengths determined from asteroidalairbursts and can be used to predict properties of to the 100 m scale. In addition, our analysis shows that meter-scale boulders on asteroidsare significantly weaker than small pieces of meteorites, while large meteoritessurviving on Earth are selected by attrition. Further, the common use of terrestrial analog materials to predict scale-dependent strength properties significantly overestimates the strength of meter-sized asteroidalmaterials and therefore is unlikely well suited for the modeling of asteroiddisruption and fragmentation. Given the strength scale-dependence determined for carbonaceous and ordinary chondrite meteorites, our results suggest that boulders of similar composition on asteroidswill have compressive strengths significantly less than typical terrestrial rocks.