Comparison of ionospheric observations and dynamical predictions of meteor showers at Mars. Withers, Mendillo, Paetzold, Tellmann, Christou, Vaubaillon The influx of meteoroids into the martian atmosphere can produce a sporadic plasma layer at 90 km altitude, below the main ionospheric layers. This meteoric layer has been observed in over one hundred electron density profiles from the radio science experiments on Mars Global Surveyor and Mars Express. Most meteoric layer observations are concentrated in narrow seasonal intervals with widths of 5-10 degrees of Ls. The occurrence of layers in narrow seasonal intervals is caused by meteor showers. Sporadic meteors cause meteoric layers that are observed occasionally at all seasons. We compare the seasons at which meteoric layers have been observed on Mars to the seasons at which meteoroid streams are predicted to approach Mars. Parent comets for several meteor showers at Mars will be identified. Control/Tracking Number: 07-RC-172-AAS-DPS Activity: Research Contributed Current Date/Time: 7/25/2007 4:20:32 PM