Astrogeology is the study of the physical properties of celestial bodies, such as their composition, structure, and surface features.

Cosmology is the study of the origin and evolution of the universe, including its large-scale structure and the properties of its contents.

The Big Bang Theory is the prevailing cosmological model for the universe from the earliest known periods through its present expansion and cooling.

The Cosmic Microwave Background is the remnant radiation of the Big Bang, which is a faint glow of light that fills the entire universe.

Cosmic Expansion is the expansion of the universe, which is observed by the redshift of distant galaxies.

Dark Energy is a hypothetical form of energy that is thought to be responsible for the accelerating expansion of the universe.

The Big Freeze is the fate of the universe in which it continues to expand forever, eventually reaching a state of maximum entropy.

The Big Crunch is the fate of the universe in which it eventually collapses back in on itself, resulting in a singularity.

The Big Rip is the fate of the universe in which it is eventually torn apart by its own expansion, resulting in the destruction of all matter.

The Heat Death is the fate of the universe in which it reaches a state of maximum entropy and all energy is evenly distributed, resulting in a state of equilibrium.

Planetary Science is the study of the physical properties of planets and other celestial bodies, such as their composition, structure, and surface features.

Astrophysics is the branch of astronomy that focuses on the study of stars, their properties, and their evolution.

Dark Matter is a hypothetical form of matter that is thought to make up a large portion of the universe but does not interact with electromagnetic radiation.

A Neutron Star is the remnant of a massive star that has undergone a supernova explosion, resulting in a dense core of neutrons.

Galactic Astronomy is the study of the properties and evolution of galaxies, including their structure, composition, and dynamics.