Masha Allah. Alhamdulillah.
My computation of approximate terminal velocity is 2.6 Mach. Missiles fired at approx. 45 degrees angle, initial two seem to take a normal ballistic trajectory, final two seem to take depressed trajectory. The terminal shots cannot be assumed to be in order. Terminal angles range from perpendicular to ground to 60 degrees from ground (approx.) Direction of shadows seems to suggest an east to west firing in the 11 am - 12 pm time frame. Interestingly, in a west to east firing, the terminal velocity will be naturally increased due to relative motion of earth. I wouldn't be surprised if the missile can achieve beyond Mach 4 in such a scenario.