Complex sentence: The aberration of light (also referred to as astronomical aberration or stellar aberration) is a relativistic which causes objects to appear displaced to moving observers, which is important in astronomy where it causes an apparent motion of celestial objects about their locations in the sky.
Split into simpler sentences: The aberration of light (also referred to as astronomical aberration or stellar aberration) is a relativistic which causes objects to appear displaced to moving observers. It is important in astronomy where it causes an apparent motion of celestial objects about their locations in the sky.