Hydrodynamics pressure due to relative motion of the terrestrial comet whenapproaching the Sun is simulated in two-dimensional space. The ambient solar windintroduced relative momentum on the comet materials. The material evaporates andleft behind the comet-head as a tail. Direction of the tail-vector always opposes to the-directionof motion if it is still far enough from the Sun. Before a tail is formed, it isobvious from our simulations that outer-most soft material will firstly dismantle andevaporate. The soft material is blown away and the tail is formed subsequently.Keywords: Solar wind, hydrodynamic simulations, comet tail formation. Bambang SetiahadiIndonesian National Institute of Aeronautics and Space (LAPAN)Watukosek, Gempol,P.O.Box04,Pasuruan67155,EastJavaPhone:0343851887,Fax:0343852311,HP:085648626737e-mail: bsetiapx14@yahoo.co.id
