Season
Season 1 Episode
- Season 1 Introduction to Astronomy
- Season 1 Naked Eye Observations
- Season 1 Cycles in the Sky
- Season 1 Moon Phases
- Season 1 Eclipses
- Season 1 Telescopes
- Season 1 The Gravity of the Situation
- Season 1 Tides
- Season 1 Introduction to the Solar System
- Season 1 The Sun
- Season 1 The Earth
- Season 1 The Moon
- Season 1 Mercury
- Season 1 Venus
- Season 1 Mars
- Season 1 Jupiter
- Season 1 Jupiter's Moons
- Season 1 Saturn
- Season 1 Uranus & Neptune
- Season 1 Asteroids
- Season 1 Comets
- Season 1 The Oort Cloud
- Season 1 Meteors
- Season 1 Light
- Season 1 Distances
- Season 1 Stars
- Season 1 Exoplanets
- Season 1 Brown Dwarfs
- Season 1 Low Mass Stars
- Season 1 White Dwarfs & Planetary Nebulae
- Season 1 High Mass Stars
- Season 1 Neutron Stars
- Season 1 Black Holes
- Season 1 Binary and Multiple Stars
- Season 1 Star Clusters
- Season 1 Nebulae
- Season 1 The Milky Way
- Season 1 Galaxies, Part 1
- Season 1 Galaxies, Part 2
- Season 1 Gamma-Ray Bursts
- Season 1 Dark Matter
- Season 1 The Big Bang, Cosmology Part 1
- Season 1 Dark Energy, Cosmology Part 2
- Season 1 A Brief History of the Universe
- Season 1 Deep Time
- Season 1 Everything, The Universe...And Life
Crash Course Astronomy - Season 1 Episode 39 Galaxies, Part 2
8.00 12 minutes Active galaxies pour out lots of energy, due to their central supermassive black holes gobbling down matter. Galaxies tend not to be loners, but instead exist in smaller groups and larger clusters. Our Milky Way is part of the Local Group, and will one day collide with the Andromeda galaxy. Clusters of galaxies also clump together to form superclusters, the largest structures in the Universe. In total, there are hundreds of billions of galaxies in the Universe.
