Astronomy Practice Exam 2025 – Complete Preparation Guide

The action of spinning an object around an imaginary axis is referred to as rotation. This term specifically denotes the movement of an object such that it turns around a central point or axis, allowing different parts of the object to move through space while remaining in a consistent orientation relative to that axis.

For example, the Earth rotates around its own axis, which is an imaginary line that runs from the North Pole to the South Pole. This rotation is what causes day and night as different parts of the Earth move into and out of sunlight.

In contrast, revolution describes the movement of one object around another object, such as the Earth revolving around the Sun. Orbit refers to the path that an object takes as it revolves, while translation generally refers to the movement of an object from one location to another without rotation or revolution. Thus, the term rotation is correctly used to describe the spinning motion around an axis.