calculation of trajectory of astroid collide with the earth with runge kutta.

Using second order differential equations,using gravitation law
of two objects m1=astroide,comet m2=earth


F=G*(m1*m2)/r^2, F=m*a=m*dv/dt ,v=dx/dt

when m1 near earth with some initial velocity.

How you can make simulation of position of m1 will collide with the earth.


(some info : can so implement kepler laws in the problem),
what I want to know is the position at each moment in time.

what is influence of the moon in the problem.

can also easy implemented in the simulation.