In today's Crash Course Astronomy, Phil takes a look at the explosive history of our cosmic backyard. We explore how we went from a giant ball of gas to the ...
Phil takes us for a closer (eye safe!) look at the two-octillion ton star that rules our solar system. We look at the sun's core, plasma, magnetic fields, sunspots, ...
This week we build on our naked eye observations from last week and take a look at the cyclical phenomena that we can see at work in the universe. -- Table of ...
In this episode of Crash Course Astronomy, Phil takes you through the cause and name of the Moon's phases. -- Why the Moon Has Phases 0:36.1 Spheres in ...
Join Phil for a tour of our capital-M Moon, from surface features, inside to the core, and back in time to theories about its formation. This episode is brought to you ...
Today Phil explores the world of tides! What is the relationship between tides and gravity? How do planets and their moons become tidally locked? What would ...
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 ...
Saturn is the crown jewel of the solar system, beautiful and fascinating. It is a gas giant, and has a broad set of rings made of ice particles. Moons create gaps in ...
Today on Crash Course Astronomy, Phil explains comets. Comets are chunks of ice and rock that orbit the Sun. When they get near the Sun the ice turns into ...
Today Phil explains that YES, there are other planets out there and astonomers have a lot of methods for detecting them. Nearly 2000 have been found so far.
In order to understand how we study the universe, we need to talk a little bit about light. Light is a form of energy. Its wavelength tells us its energy and color.
How do astronomers make sense out of the vastness of space? How do they study things so far away? Today Phil talks about distances, going back to early ...
Gamma-ray bursts are not only incredible to study, but their discovery has an epic story all its own. Today Phil takes you through some Cold War history and then ...
One last round of laughs with Phil as he struggles through some Bad Astronomy. -- Crash Course Astronomy Poster: ...
Today we're talking about our galactic neighborhood: The Milky Way. It's a disk galaxy, a collection of dust, gas, and hundreds of billions of stars, with the Sun ...
While Jupiter is nowhere near massive enough to initiate fusion in its core, there are even more massive objects out there that fall just short of that achievement ...
Massive stars fuse heavier elements in their cores than lower mass stars. This leads to the creation of heavier elements up to iron. Iron robs critical energy from ...
Today Phil follows up last week's look at the death of low mass stars with what comes next: a white dwarf. White dwarfs are incredibly hot and dense objects ...
The fourth planet from the sun and the outermost of the terrestrial planets, Mars has long been a popular spot for missions and imagination. Phil walks you ...
Venus is a gorgeous naked-eye planet, hanging like a diamond in the twilight -- but it's beauty is best looked at from afar. Even though Mercury is closer to the ...
Phil starts the planet-by-planet tour of the solar system right here at home, Earth. -- Table of Contents Earth is a Planet 0:03 Layers of Earth 1:25 The Magnetic ...
After 10 information-heavy episodes, it's time for a little Bad Astronomy. -- PBS Digital Studios: http://youtube.com/pbsdigitalstudios Follow Phil on Twitter: ...
Astronomers study a lot of gorgeous things, but nebulae might be the most breathtakingly beautiful of them all. Nebulae are clouds of gas and dust in space.
Jupiter is the biggest planet in our solar system. The gas giant is NOT a failed star, but a really successful planet! It has a dynamic atmosphere with belts and ...
The big question in the comments last week was, "BUT WHAT ABOUT ECLIPSES?" Today, Phil breaks 'em down for you. This episode is sponsored by ...
Now that we've finished our tour of the planets, we're headed back to the asteroid belt. Asteroids are chunks of rock, metal, or both that were once part of ...
In today's episode, Phil looks at how gravity plays out across the universe. This episode is sponsored by Squarespace: ...
Welcome to the first episode of Crash Course Astronomy. Your host for this intergalactic adventure is the Bad Astronomer himself, Phil Plait. We begin with ...
Today on Crash Course Astronomy, Phil invites you to head outside and take a look at all the incredible things you can see with your naked eye. -- Table of ...
Today we're rounding out our planetary tour with ice giants Uranus and Neptune. Both have small rocky cores, thick mantles of ammonia, water, and methane, ...
Today Phil explains how telescopes work and offers up some astronomical shopping advice. -- How Telescopes Work 1:07 Refractors vs Reflectors 2:50 ...
In which John Green, Hank Green, and Emily Graslie teach you about, well, everything. Big History is the history of everything. We're going to start with the Big ...
As we approach the end of Crash Course Astronomy, it's time now to acknowledge that our Universe's days are numbered. Stars will die out after a few trillion ...
Finally, after what seems like eons and eons, the end is nigh. We're talking not only about the end of Crash Course Big History, but also the end of everything.
We've covered a lot of incredible stuff, but this week we're talking about the weirdest objects in space: BLACK HOLES. Stellar mass black holes form when a ...
Today Phil helps keep you from ticking off an astronomer in your life by making sure you know the difference between a meteor, meteorite, and meteoroid.
Here it is, folks: the end. In our final episode of Crash Course Astronomy, Phil gives the course a send off with a look at some of his favorite topics and the big ...