Impact-Chronology Model as Mass-Estimate Method for Impacted Masses on Planetary Surfaces

Introduction: The solar system has undergone a bombardment by small bodies, documented by cratering records on planetary surfaces as seen in image-investigations since the early 1960’s. The well investigated lunar cratering record reveals a typical size-frequency distribution (SFD) leading to the well known impact-chronology model proposed by [1],[2]. Comparisons of size-frequency distributions of the cratering-record on surfaces of planetary bodies of the inner solar system with the observed Near-Earth-Asteroid (NEA) population of the the asteroid belt [2], [3], [4] has led to the conclusion that the asteroid belt acts as the major contributor of the impactor population for the planetary bodies of the inner solar system. This is, however, still in discussion for the outer solar system, especially for the Jovian and Saturnian system. Recent measurements of the impact crater-size frequency distribution on surfaces of moons in the Saturnian system and comparisons with the lunar-like crater size-frequency distribution also lead to the conclusion, that the asteroid belt is also a major contributor of impactors to the Jovian and Saturnian system [5]. Methods: In order to support the conclusion that the asteroid belt acts as the major contributing source for impactors for both the planetary bodies of the inner solar system and the planetary bodies of the Jovian and Saturnian system, the total mass impacted on the surfaces of planetary bodies is estimated with impactchronology models derived from measurements of the size-frequency distribution of the lunarcratering record as proposed by [1]. An estimate of the total impacted mass on the surface of planetary bodies is performed under the assumption of a common time-invariant size-frequency distributed population of impactors and the application of a suitable scaling law, by mapping crater size-frequency into impactor size-frequency distributions, as proposed by [6], [7], [8]. With the assumption of an average impactor density, an average impact angle and an average impact velocity, the diameter of the impactor can be approximated from the impact-crater diameter. Furthermore, its mass can be estimated by the assumption of a spherical shape. Body SFD CHR M [1.0E20 kg] R [1.0E-03]