Have you ever wondered if there is anyone (or anything) else out there in the universe? Well, you're not alone. But what would alien life look like? And what would their food chains and food webs look like? In this episode of Crash...

Population III stars were the very first stars in our universe and far larger than any we can see today. Where are they now?

Paul Andersen explains three major nuclear processes; fusion, fission, and decay. He begins with a brief discussion of the four fundamental forces in nature. He the explains how nuclei can be combined in fusion, divided through...

Today Hank brings us the news of a unique astronomical discovery - a rogue planet. He also allays our fears of an apocalyptic collision with Earth. So, this new planet is awesome, but it needs a different name - CFBDSIR...

Did you know that gold is extraterrestrial? Instead of arising from our planet's rocky crust, it was actually cooked up in space and is present on Earth because of cataclysmic stellar explosions called supernovae. CERN Scientist David...

Paul Andersen describes our place on the Earth in the Solar System within the Milky Way Galaxy in the Universe. The make-up and origins of the Universe are included along with stellar evolution. A teaching progression K-12 is also...

Maybe you've seen a shooting star, a bright streak of light that zips across the sky! But did you know that those shooting stars are actually rocks falling from space? And sometimes you can find them on the ground! Find out how...

Voyager 2 is the second object to leave our solar system, which means we now have twice as much information about its edges! And scientists have found a record-breaking black hole.

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, solar flares, coronal mass ejections, and what all of that means for our...

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 Bang, take you right through all of history (recorded and otherwise), and...

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...

The Milky Way is our neighborhood in the universe. It’s a galaxy and there are many others out there. Galaxies contain gas, dust, and billions of stars or more. They come in four main shapes: elliptical, spiral, peculiar, and irregular....

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 answering a question: "What is astronomy?"

Research suggests that nearly every star has at least one planet, but we haven't found any other solar systems that look quite like ours.

If you think scientists lead boring, monotonous lives, you must not know about Tycho Brahe. The 16th century astronomer who accurately predicted planetary motion led quite a dramatic life -- complete with a kidnapping, a sword duel and...

Today Phil’s explaining the stars and how they can be categorized using their spectra. Together with their distance, this provides a wealth of information about them including their luminosity, size, and temperature. The HR diagram plots...

Or why we live on an onion made of magma

What exactly will happen when the sun dies?

Everything in our universe has mass - from the smallest atom to the largest star. But the amount of mass has remained constant throughout existence even during the birth and death of stars, planets and you. How can the universe grow...

So, you know about stars. But what if those stars formed a super group like The Avengers? Well, then you have a Constellation! In this episode of Crash Course Kids, Sabrina chats about stars, constellations, and how humans have used...

Let's say you're looking for a specific constellation in the sky, but can't find it? That could be because you're on the wrong part of the planet to see it. In this episode of Crash Course Kids, Sabrina talks about how the Earth's...

Last week we talked about the orbits of the Earth and our Moon. But today we're going to go a little bigger... well, a lot better. Did you know that there is a massive Black Hole at the center of our Galaxy? Or that Pluto's orbit is...

Stellar astronomer and TED Senior Fellow Lucianne Walkowicz works on NASA's Kepler mission, searching for places in the universe that could support life. So it's worth a listen when she asks us to think carefully about Mars. In this...

So, what is the Ecliptic? Well, it has to do with the Zodiac constellations and our sun and how they move in relation to one another. It's kind of cool! In this episode, Sabrina chats about this imaginary line called the Ecliptic and its...