Question

if earth had no atmosphere, would a falling object ever reach terminal velocity?

Answer 1

I believe the answer is yes. If earth had no atmosphere, a falling object will still reach terminal velocity. Terminal velocity is the point at which the drag force equals the force of gravity. It is a function of gravity and gravity is still present so it reaches terminal velocity.

Answer 2

The lack of an atmosphere renders terminal velocity meaningless, for terminal velocity Is the state where the effects of resistance on an object falling through a medium (the medium in this case being the atmosphere) is inversely equal to that of gravity, thus preventing further acceleration. So in the absence of an atmosphere there would be no effects of atmospheric drag and only the effect of gravity would be felt, allowing for infinite acceleration.