Complex sentence: It is important in astronomy and astrometry as it causes an apparent motion of celestial objects about their locations in the sky, and it was historically influential in the development of the theories of heliocentrism, light, luminiferous aether, and Special Relativity.
Split into simpler sentences: It is important in astronomy and astrometry as it causes an apparent motion of celestial objects about their locations in the sky. It was historically influential in the development of the theories of heliocentrism, light, luminiferous aether, and Special Relativity.