Inertia is the property of a body of matter. It is described in Newton’s first law that an object will tend to remain at rest or move in a straight line at a constant speed unless a force acts on the object. The higher the mass of an object the higher its inertia.
Explanation:
In the vacuum of space, this is certainly evident because a celestial mass like an asteroid can move in a straight line for over billions of light-years with more or less the same speed unless another force of the universe such as gravity and dark energy act on this object. The reason this is less evident on earth is due to gravity and air resistance of the atmosphere that will quickly reduce the speed on an object and change its trajectory.
