Final answer:
Astronomy is considered a natural science because it uses empirical evidence and scientific methods in its study of celestial objects and phenomena. Astrology, which does not rely on such evidence and does not employ the scientific method, is not classified as a natural science.
Step-by-step explanation:
Astronomy and astrology both study the stars, but astronomy is considered a natural science. This classification stems from astronomy's use of empirical evidence and scientific methods to understand celestial phenomena. Astronomy is a branch of the physical sciences and relies on the laws of physics to make observations and predictions about events in the sky. For example, astronomers use telescopes and other instruments to gather data about planets, stars, galaxies, and other celestial objects, applying our understanding of physics, mathematics, and chemistry to interpret these observations.
On the contrary, astrology, which claims to discern the influence of celestial bodies on human affairs, does not follow the scientific method and is not supported by empirical evidence. Therefore, it is not considered a natural science. The natural sciences include disciplines such as astronomy, biology, chemistry, earth science, and physics, and are characteristically known as "hard sciences" due to their reliance on quantitative data.
Some experts categorize the natural sciences into life sciences, which includes biology, and physical sciences, which includes astronomy, geology, physics, and chemistry. Astronomy, specifically, has even been described as an observational science that uses sophisticated instruments and technology to observe astronomical objects, testing hypotheses with this acquired data, similar to how laboratory experiments are conducted and evaluated.