Abstract

Session
Comets: Rosetta results and related science
Title of Abstract
METEOR SHOWER ON MARS INDICATES COMETARY ACTIVITY FAR AWAY FROM THE SUN
Author
ASWIN SEKHAR
Co-Authors
DAVID ASHER (ARMAGH OBSERVATORY, NORTHERN IRELAND)
Institution
ARMAGH OBSERVATORY, NORTHERN IRELAND
Summary (maximum 250 words)
Introduction: The close encounter of Comet C/2013 A1 (Siding Spring) with Mars on 2014 Oct 19 generated a lot of interest and modelling work [1] [2] [3] in the solar system community. A press release from NASA implied that a meteor shower was detected on Mars by their space instruments some hours after the comet-Mars close encounter. Various work [4] [5] [6] has suggested that very specific meteoroid sizes and ejection conditions may be required to produce meteor phenomena at Mars at the given times.
Dynamics: Meteoroid stream modelling have gained high precision over the years. Here we compute the structure of the cloud of meteoroids released by comet, showing its dependence on heliocentric ejection distances, 3-dimensional ejection velocities, and particle sizes. Our calculations using numerical integrator MERCURY, [7], incorporating radiation pressure, [8], show that ejection of particles at large heliocentric distances could lead to evolution of a dense meteoroid cloud which intersects Mars a few hours after the comet-Mars close encounter. This detection of a meteor shower on Mars is an indirect confirmation of cometary activity at large distances which has rarely been observed directly by telescopes so far.
References: [1] Vaubaillon J., Macquet L., Soja R. 2014. MNRAS. 439: 3294. [2] Moorhead A. V., Wiegert P. A., Cooke W. J. 2014. Icarus. 231:13. [3] Ye Q.-Z., Hui M.-T., 2014, ApJ, 787: 115. [4] Farnocchia D. et al. 2014. ApJL. 790: 114. [5] Kelley M. S. P. et al. 2014, ApJL, 792: 16. [6] Tricarico P. et al., 2014, ApJL, 787: 35. [7] Chambers J. E. 1999. MNRAS. 304: 793. [8] Burns J. A, Lamy P. L., Soter S. 1979. Icarus. 40: 1.
Attachment

Schedule

Session Time
09:00 - 10:30
Talk start
10:15
Day
Monday

RASLogo