Collisionless shocks in space plasma are regions of heating and
acceleration of charged particles and dissipation of kinetic energy.
These accelerated particles are the source of electromagnetic emissions
from supernova remnants and other astrophysical structures. At high Mach
numbers, shocks can be inherently nonstationary and exhibit modulated
energy transfer and recurring plasma compression areas in the form of
reformation. We use data from the Mars Atmosphere and Volatile Evolution
(MAVEN) spacecraft to study reformation of the Martian bow shock which
has a relatively high curvature compared to that at Earth and the
upstream solar wind is often mass loaded with a population of pickup
ions. We show evidence of ion reflection effects in reformation of a
supercritical quasi-perpendicular shock.