Which statement supports newton’s first law of motion? planets can change the direction of their own orbital path. planets with more inertia will not be impacted by the sun’s gravity. planets can move at a varying speed due to forces exerted in space. planets with a greater mass will orbit more quickly than smaller planets.

The correct answer is  C.  Planets can move at a varying speed due to forces exerted in space.

Any moving object in space will travel in a straight line at the same speed forever, planets included. The planets would be moving in straight lines, but the sun’s gravity pulls them toward it, the force of gravity causes the moving planets to travel in roughly circular orbits around the sun.

(They have been circling the sun for billions of years because other forces have been too weak to change the orbits in any significant way)