Crash Course Astronomy | GBH

Crash Course Astronomy

Welcome to school without the classroom! Join host Phil Plait and discover everything there is to know about the cosmos.

Episode 46, Season 1
Life in the Universe: Crash Course Astronomy #46

Phil gives the course a send off with a look at some of his favorite topics.

11:09
Episode 45, Season 1
Deep Time: Crash Course Astronomy #45

Our Universe’s days are numbered.

15:00
Episode 44, Season 1
A Brief History of the Universe: Crash Course Astronomy #44

Thanks to the wonders of physics, we can map a timeline of the universe’s history.

12:21
Episode 43, Season 1
Dark Energy, Cosmology part 2: Crash Course Astronomy #43

Most of the universe is made up of a mysterious entity that pervades space: dark energy.

11:08
Episode 42, Season 1
The Big Bang, Cosmology part 1: Crash Course Astronomy #42

Thanks to observations of galaxy redshifts, we can tell that the universe is EXPANDING!

13:09
Episode 41, Season 1
Dark Matter: Crash Course Astronomy #41

Today on Crash Course Astronomy, Phil dives into some very dark matters.

11:45
Episode 40, Season 1
Gamma-Ray Bursts: Crash Course Astronomy #40

The discovery of gamma-ray bursts is an epic story.

13:51
Episode 39, Season 1
Galaxies, part 2: Crash Course Astronomy #39

Active galaxies pour out lots of energy.

15:20
Episode 38, Season 1
Galaxies, part 1: Crash Course Astronomy #38

Galaxies contain gas, dust, and billions of stars or more.

11:51
Episode 37, Season 1
The Milky Way: Crash Course Astronomy #37

Today we’re talking about our galactic neighborhood: The Milky Way.

10:59
Episode 36, Season 1
Nebulae: Crash Course Astronomy #36

Astronomers study a lot of things, but nebulae might be the most beautiful of them all.

12:01
Episode 35, Season 1
Star Clusters: Crash Course Astronomy #35

Last week we covered multiple star systems, but what if we added thousands to the mix?

10:21
Episode 34, Season 1
Binary and Multiple Stars: Crash Course Astronomy #34

Binary stars are gravitationally bound together in the same system.

11:46
Episode 33, Season 1
Black Holes: Crash Course Astronomy #33

Stellar mass black holes form when a very massive star dies, and its core collapses.

12:11
Episode 32, Season 1
Neutron Stars: Crash Course Astronomy #32

In the aftermath of a some stars we find a weird little object known as a neutron star.

12:42
Episode 31, Season 1
High Mass Stars: Crash Course Astronomy #31

Massive stars fuse heavier elements in their cores than lower mass stars.

12:02
Episode 30, Season 1
White Dwarfs & Planetary Nebulae: Crash Course Astronomy #30

What comes next after the death of a low mass star? A white dwarf.

11:09
Episode 29, Season 1
Low Mass Stars: Crash Course Astronomy #29

Today we are talking about the life -- and death -- of stars.

12:02
Episode 28, Season 1
Brown Dwarfs: Crash Course Astronomy #28

Brown dwarfs have a mass that places them between giant planets and small stars.

11:05
Episode 27, Season 1
Exoplanets: Crash Course Astronomy #27

There are many other planets outside of our own solar system, but finding them is tricky.

11:49
Episode 26, Season 1
Stars: Crash Course Astronomy #26

Phil explains stars and how they can be categorized using their spectra.

10:40
Episode 25, Season 1
Distances: Crash Course Astronomy #25

How do astronomers make sense out of the vastness of space?

11:20
Episode 24, Season 1
Light: Crash Course Astronomy #24

In order to understand more of universe, we need to talk a little bit about light.

10:33
Episode 23, Season 1
Meteors: Crash Course Astronomy #23

What the difference between a meteor, meteorite, and meteoroid?

11:21
Episode 22, Season 1
The Oort Cloud: Crash Course Astronomy #22

We're heading to the outskirts of the solar system.

11:40
Episode 21, Season 1
Comets: Crash Course Astronomy #21

Comets are chunks of ice and rock that orbit the Sun.

11:54
Episode 20, Season 1
Asteroids: Crash Course Astronomy #20

Now that we've finished our tour of the planets, we're headed back to the asteroid belt.

11:32
Episode 19, Season 1
Uranus & Neptune: Crash Course Astronomy #19

We're rounding out our planetary tour with ice giants Uranus and Neptune.

12:15
Episode 18, Season 1
Saturn: Crash Course Astronomy #18

Saturn is the crown jewel of the solar system, beautiful and fascinating

12:12
Episode 17, Season 1
Jupiter's Moons: Crash Course Astronomy #17

Before moving on from Jupiter, we're going to linger for a moment on the planet's moons.

10:26
Episode 16, Season 1
Jupiter: Crash Course Astronomy #16

Jupiter is the biggest planet in our solar system.

10:42
Episode 15, Season 1
Mars: Crash Course Astronomy #15

Mar is the fourth planet from the sun and the outermost of the terrestrial planets.

10:11
Episode 14, Season 1
Venus: Crash Course Astronomy #14

Venus is a gorgeous naked-eye planet, hanging like a diamond in the twilight.

10:46
Episode 13, Season 1
Mercury: Crash Course Astronomy #13

Mercury is the closest planet to the sun.

10:17
Episode 12, Season 1
The Moon: Crash Course Astronomy #12

Take a look up to the moon's surface features, core, and theories about its formation.

9:47
Episode 11, Season 1
The Earth: Crash Course Astronomy #11

Phil starts the planet-by-planet tour of the solar system right here at home, Earth.

10:13
Episode 10, Season 1
The Sun: Crash Course Astronomy #10

Take a look at the two-octillion ton star that rules our solar system.

11:44
Episode 9, Season 1
Introduction to the Solar System: Crash Course Astronomy #9

Phil takes a look at the explosive history of our cosmic backyard.

9:57
Episode 8, Season 1
Tides: Crash Course Astronomy #8

What is the relationship between tides and gravity?

9:46
Episode 7, Season 1
The Gravity of the Situation: Crash Course Astronomy #7

Phil looks at how gravity plays out across the universe.

9:41
Episode 6, Season 1
Telescopes: Crash Course Astronomy #6

Today Phil explains how telescopes work

11:59
Episode 5, Season 1
Eclipses: Crash Course Astronomy #5

"But what about eclipses!?"

10:10
Episode 4, Season 1
Moon Phases: Crash Course Astronomy #4

Phil takes you through the cause and name of the Moon's phases.

9:45
Episode 3, Season 1
Cycles in the Sky: Crash Course Astronomy #3

Take a look at the cyclical phenomena that we can see at work in the universe.

9:28
Episode 2, Season 1
Naked Eye Observations: Crash Course Astronomy #2

Take a look at all the incredible things you can see with your naked eye.

11:16
Episode 1, Season 1
Introduction to Astronomy: Crash Course Astronomy #1

Get to know host Phil Plait and begin with answering a simple question: what is astronomy?

12:11

Become a GBH sponsor

What matters to you.

© 2025 WGBH. All rights reserved.

Our Partners