  In this paper, we propose a 3D kinetic model (Particle-in-Cell PIC ) for the
description of the large scale Earth's bow shock. The proposed version is
stable and does not require huge or extensive computer resources. Because PIC
simulations work with scaled plasma and field parameters, we also propose to
validate our code by comparing its results with the available MHD simulations
under same scaled Solar wind ( SW ) and ( IMF ) conditions. We report new
results from the two models. In both codes the Earth's bow shock position is
found to be ~14.8 RE along the Sun-Earth line, and ~ 29 RE on the dusk side.
Those findings are consistent with past in situ observations. Both simulations
reproduce the theoretical jump conditions at the shock. However, the PIC code
density and temperature distributions are inflated and slightly shifted sunward
when compared to the MHD results. Kinetic electron motions and reflected ions
upstream may cause this sunward shift. Species distributions in the foreshock
region are depicted within the transition of the shock (measured ~2
c/{\omega}pi for {\Theta}Bn =90o and MMS =4.7 ) and in the downstream. The size
of the foot jump in the magnetic field at the shock is measured to be (1.7
c/{\omega}pi ). In the foreshocked region, the thermal velocity is found equal
to 213 km.sec-1 at 15 RE and is equal to 63 km.sec-1at 12 RE (Magnetosheath
region). Despite the large cell size of the current version of the PIC code, it
is powerful to retain macrostructure of planets magnetospheres in very short
time, thus it can be used for a pedagogical test purposes. It is also likely
complementary with MHD to deepen our understanding of the large scale
magnetosphere
