Estimation of the trajectory of meteoroids from Martian clusters

Abstract

Recently, about 1200 fresh meteoroid impact sites were discovered on Mars, they are single craters and crater fields with crater sizes up to 50 m. Atmosphere density on the surface of Mars corresponds to about 30 km height of the Earth's atmosphere. Thus, scattering fields of craters on Mars allow one to study fragmentation details, which are hidden in terrestrial conditions. Previously, data on 77 Martian clusters were analyzed. To estimate the trajectory of meteoroids, the scattering ellipses were constructed. The ellipse size determines the angle of the meteoroid entry into the atmosphere and provides information about the height of destruction and the density of a space object. For more than 70% of clusters, the obtained azimuth estimations are within 20° of those determined by independent evaluations. For some clusters, the flight direction can be specified from crater ejecta on Martian HiRISE images. Estimations of azimuth angles for 42 clusters coincide with previous results obtained for 70% of clusters, while the data on the flight direction fit only for 30%. The discrepancy between different estimations of azimuth angles requires the use of other approaches. Continuing on the topic, this work presents numerical modeling of the flight and fragmentation of a meteoroid in the atmospheres of two planets, Mars and Earth. It is assumed that the simulation results will allow one to determine meteoroid parameters, in particular, the trajectory parameters. The main purpose of the presented work is to demonstrate the efficiency of the fragmentation model, its applicability to Martian clusters, and the difference in the scattering fields on the Earth and Mars: the atmospheric sorting effect is weak on Mars, and the scattering field is mainly dependent on fragmentation and the lateral spreading of fragments. The area of the simulated cluster is described with an accuracy of about 10%; the size of the maximum crater, with an accuracy of about 35%. The ratios of crater diameters to the maximum crater diameter for the model and real cluster are close to each other. In the future, it is planned to implement a series of numerical simulations with different initial data and to compare the results with real clusters on Mars, which have already been analyzed in previous works. The aim is to propose the advanced methods for determining the direction of the flight of meteoroids and the properties of impactors such as density and strength.