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 statement that supports Newton's first law of motion is the one that says that planets can move at a varying speed due to forces exerted in space.

Explanation:

Newton's first law of motion states that, if no resulting force acts on an object, no change in speed of that object can occur. The speed will therefore remain unchanged: both size and direction of the speed will remain constant. Therefore, the object will remain stationary (speed 0) or move at a constant speed in a certain direction.

The first law is also called the law of inertia: an object on which no external forces work is at rest or performs a unified rectilinear movement. To change the state of motion of an object requires a force.