Linking a large oblique-impact crater on Mars to the Southern Mt Lofty Ranges multiple impact event in South Australia – inference for latter event size and scope

Understanding of shallow angle impacts (termed "oblique") comes from planetary bodies other than Earth, and also comes from modelling published by various workers over the past two decades or so. Another comparator source is the Southern Mt Lofty Ranges and Kangaroo Island impact in South Australia, which has not been dated other than being >35 mya. At previous conference attendances the case has been built that the oblique impact in SA was from the south rather than in the plane of the ecliptic, which raises the new question how common is such an event in the solar system. A digital elevation model from the Mars Orbiter Laser Altimeter has here been used to assess the occurrences of oblique impacts on Mars, focussing on the northern hemisphere. A large impact crater at 7 degrees N / 178 degrees E on Mars matches the criteria and additionally has the same impact approach direction as the Southern Mt Lofty Ranges craters, implying that the orbital plane of that impactor may have been similar or the same as that of the latter. The large scale of the particular crater identified on Mars forces a reassessment of the sizes of additional candidate Australia craters beyond the Southern Mt Lofty Ranges and Kangaroo Island impact sites. A digital elevation model of a central band of Australia, some 600 km wide, is analysed for candidate sites, while indicators of meteorite disintegration during oblique impacts are used to inform the study and to shortlist candidate sites.