1. The problem statement a comet gets in the way of the Halley asteroid, so the question is: what's the new trajectory of the asteroid (its excentricity, its orbital rotation and it perihelion, aphelion) both objects have same mass and we suppose that the comet have an negilgeable initial velocity. all variables and given/known data what we know is :both objects have same mass M=2.2*10^14 kg the coefficient of restitution during collision is: 0.5 orbital period of Halley's asteroid: T=75.3 years initial perihelion: 0.586 AU initial excentricity: 0.967 2. Relevant equations the kepler third law conservation of angular momentum relation between energy and excentricity equation and trajectory of asteroid are attached 3. The attempt at a solution my attempts are to use the conservation of energy and angular momentum but i didn't know how to get the parameters of the trajectory from.