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Evolution of an impact crater on Hyperion

Evolution of an impact crater on Hyperion
Evolution of an impact crater on Hyperion An explanation for how Hyperion got its "spongy" appearance, based on a model proposed at the 2011 Lunar and Planetary Science Conference by Alan Howard and coauthors. Due to Hyperion's low gravity, most of the debris tossed outward from an impact crater (A & B) would be lost from Hyperion, going instead into orbit around Saturn. Whereas craters on other bodies, like the Moon, Mars or Mercury, initially have a rim and ejecta deposits outside the crater, Hyperion would lack these. Also, since not much ejecta falls back to the surface following an impact, there would not be an intracrater plain created on the surface. So crater saturation will occur relatively quickly on Hyperion compared to larger bodies.The release (uncapping) of volatile matrix materials along the crater walls weakens the exposed "bedrock" and causes mass-wasting (landslides) into the bottom of the crater, creating crenulated rim shapes and a debris pile at the bottom of the crater (C). Throw in a later addition of dark-colored material that collects in the unlit depths of the crater, and you get the surface we see today (D). Mike Malaska (based on a model proposed by Howard et al. 2011)