What effect does pressure from sunlight have on comets according to astrophysics?

The correct answer highlights the effect of solar radiation pressure on comets, particularly how it interacts with the comet's coma and tail. As a comet approaches the Sun, the heat from solar radiation causes the ice within the comet to sublimate, turning into gas. This process releases gas vapor and dust particles from the head of the comet, which is called the nucleus.

The pressure from the sunlight pushes these gas and dust particles away from the nucleus, resulting in the characteristic tail of the comet that always points away from the Sun. This phenomenon occurs because solar radiation exerts a force on the particles, effectively "fanning" them out in space. The appearance and direction of the comet's tail can provide valuable information about the composition and behavior of the comet as it orbits the Sun.

This understanding of how sunlight affects a comet is foundational in astrophysics, as it underscores the balance of forces at play in the solar system and the dynamic nature of these icy bodies as they travel through space.