Simulations of meteoroid impacts on Phobos and global crater distributions

Using a data base of 1037 periodic comets, we identified time of activity of potential Martian meteoroid streams. We derived a model of the cumulative particle flux as function of distance from the stream axis. The model allows estimating the probability and velocity of possible meteoroid encounters with Mars and the Martian satellites and was used for modelling of the current Phobos meteoroid bombardment. The results of stochastic modeling of meteoroid impacts on Phobos are presented

Comet population near Mars and predicted meteoroid encounters with Phobos

As we know most of the meteoric matter in the Solar system formed from the degradation of comets when they approach to the sun. Meteor situation in the region of the Earth's orbit is quite well-studied, hundreds of meteor showers are identified[2]. But we know almost nothing about the Martian meteor showers. In the present work we attempt to construct a model of the spatial distribution of meteoric matter and models of the meteoroid population in the area of the orbit of Mars (in particular for Phobos)

Orbit determination based on meteor observations using numerical integration of equations of motion

Recently, there has been a worldwide proliferation of instruments and networks dedicated to observing meteors, including airborne and future space-based monitoring systems. There has been a corresponding rapid rise in high quality data accumulating annually. In this paper, we present a method embodied in the open-source software program "Meteor Toolkit", which can effectively and accurately process these data in an automated mode and discover the pre-impact orbit and possibly the origin or parent body of a meteoroid or asteroid. The required input parameters are the topocentric pre-atmospheric velocity vector and the coordinates of the atmospheric entry point of the meteoroid, i.e. the beginning point of visual path of a meteor, in an Earth centered-Earth fixed coordinate system, the International Terrestrial Reference Frame (ITRF). Our method is based on strict coordinate transformation from the ITRF to an inertial reference frame and on numerical integration of the equations of motion for a perturbed two-body problem. Basic accelerations perturbing a meteoroid's orbit and their influence on the orbital elements are also studied and demonstrated. Our method is then compared with several published studies that utilized variations of a traditional analytical technique, the zenith attraction method, which corrects for the direction of the meteor's trajectory and its apparent velocity due to Earth's gravity. We then demonstrate the proposed technique on new observational data obtained from the Finnish Fireball Network (FFN) as well as on simulated data. In addition, we propose a method of analysis of error propagation, based on general rule of covariance transformation. (C) 2015 Published by Elsevier Ltd.Peer reviewe

Orbital evolution of ejecta from Phobos and formation of dust rings

We have studied the orbital evolution of particles ejected from Phobos by meteoroid impacts. Simulations of trajectories of the particles about Mars is performed by numerical integration for a one thousand year interval. We took into account the Mars gravity field, third body attraction and solar radiation pressure. The simulations show dust ring formation for some initial conditions. The long-term stability of rings is estimated

Orbit determination of the Kylmälä fireball

We study observations of a fireball that occurred in Kylmälä, Finland with the aim of determining its Keplerian orbital elements. The fb_entry program is used to determine the fireball’s trajectory based on the observations. The orbit is then determined using this trajectory as the input parameters with the Meteor Toolkit software. We successfully determine the fireball’s orbit, which appears to be an ordinary near-Earth asteroid orbit. We find that the fireball’s semi-major axis is 1.94 AU, which corresponds to the inner edge of the main asteroid belt and gives cause to suspect that the object originated in the main belt and evolved into a NEA due to the effect of the secular?6 resonance. Several related bodies were also identified. © 2017, Finish Environment Institute. All rights reserved.Peer reviewe

The meteoroid environment and impacts on Phobos

We review current knowledge of the flux of meteoroids on Phobos, a key to interpreting its cratering record and understanding the origin of the Martian satellite system. Past observational attempts to estimate the flux of small (mm to cm) meteoroids as meteors in the Martian atmosphere highlight the need for customised instrumentation onboard future missions bound for Mars. The temporal distribution of cometary meteoroid streams as predicted by recent work is non-uniform; we advocate emplacing seismic stations on Phobos or cameras optimised to monitor the Martian atmosphere for meteors as a means to elucidate this and other features of the meteoroid population. We construct a model of the sporadic flux of metre-sized or larger meteoroids and use it to predict a leading/trailing ratio in crater density of ~4~4 if crater production by asteroidal meteoroids dominates over that by cometary ones. It is found that the observed distribution of craters ≥100m as determined from spacecraft images is consistent with a 50/50 contribution from the two meteoroid populations in our model. A need for more complete models of the meteoroid flux is identified. Finally, the prospects for new observational constraints on the meteoroid environment are reviewed

Stability and Evolution of Orbits Around the Binary Asteroid 175706 (1996 FG3) and Asteroids 162173 (1999 JU3) and 101955 (1999 RQ36): Implications for the MARCO-POLO-R Mission

In support of the Marco-Polo-R mission, we have carried out numerical simulations of spacecraft trajectories searching for stable orbits about the asteroids 175706(1996 FG3), 1999 RQ36 and 1999 JU3 under the influence of solar radiation pressure

Orbit and dynamic origin of the recently recovered Annama's H5 chondrite

We describe the fall of Annamameteorite occurred in the remote Kola Peninsula (Russia) close to Finnish border on 2014 April 19 (local time). The fireball was instrumentally observed by the Finnish Fireball Network. From these observations the strewnfield was computed and two first meteorites were found only a few hundred metres from the predicted landing site on 2014 May 29 and 30, so that the meteorite (an H5 chondrite) experienced only minimal terrestrial alteration. The accuracy of the observations allowed a precise geocentric radiant to be obtained, and the heliocentric orbit for the progenitor meteoroid to be calculated. Backward integrations of the orbits of selected near-Earth asteroids and the Annama meteoroid showed that they rapidly diverged so that the Annama meteorites are unlikely related to them. The only exception seems to be the recently discovered 2014UR116 that shows a plausible dynamic relationship. Instead, analysis of the heliocentric orbit of the meteoroid suggests that the delivery of Annama onto an Earth-crossing Apollo-type orbit occurred via the 3:1 mean motion resonance with Jupiter or the nu6 secular resonance, dynamic mechanisms that are responsible for delivering to Earth most meteorites studied so far. © 2015 The Authors