Lunar and Planetary Science XLVIII (2017) 1726.pdf CHRONOLOGY OF FRESH RAYED CRATERS IN ELYSIUM PLANITIA, MARS. C. B. Hundal1, M. P. Golombek2, I. J. Daubar2. 1Dept. Astronomy, Whitin Observatory, Wellesley College, Wellesley, MA 02481 (
[email protected]). 2 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109. Introduction: While fresh impact craters are easily at the same distance from the primary. Using methods recognized by their high-albedo rays on the Moon and described in [5], attributes such as typical diameter and Mercury, fresh rayed craters on Mars have only been distinctive ejecta were noted for each secondary popu- identified recently in thermal infrared images [1]. The- lation. Where both populations were present, we used se rays are believed to be among the youngest geo- these attributes to determine source craters and thus morphic features on Mars; closer inspection of them superposition relationships. reveals high densities of secondary impact craters [2]. Recurrence intervals: Recurrence intervals are an Elysium Planitia has the largest concentration of iden- estimate of the average amount of time between suc- tified rayed craters on Mars, and their thermal rays cessive impacts of a given size, over a given area [6]. overlap one other in a number of regions, including the The intervals in this study are based on the Neukum et landing site for the InSight mission [3]. al. 2001 production function [7]. Recurrence intervals Similar to [4], we use superpositions of secondary (Fig. 2) are given for 30%, 50%, and 100% of Mars’ craters as seen in High Resolution Imaging Science surface for three reasons.