The deaths of massive stars results in one of the most beautiful and violent events in the universe: the supernova. But if these explosions occur too close to Earth their radiation can impact life and even trigger mass extinctions.

Cern's Large Hadron Collider routinely collides particles at energies equivalent to a fraction of a second after the Big Bang. If this worries you, then the following fact will either put you at ease or scare the hell out of you. And...

It has NO EDGE. And NO CENTER... or does it?

How do we know what the air is like on planets we haven't visited? This video explains how to see air from 150 light years away. Thanks to NASA's James Webb Space Telescope project at the Space Telescope Science Institute for supporting...

The Milky Way is often described as measuring 100,000 light years across and containing the mass of a trillion Suns. But our home galaxy is actually far bigger, and might be much less massive. Astronomers aren't sure what the exact stats...

We can get to Mars in 3 days, . . .sort of, maybe. In this episode of SciShow Space Reid Reimers explains the possibilities of photonic propulsion in use with space travel.

Space is pretty deadly. But is it so deadly that we’re effectively imprisoned in our solar system forever? Many have said so, but a few have actually figured it out.

There’s an absolute limit to our access to the universe beyond our own galaxy. There’s a limit to what we can ever hope to explore or send signals to, and a very different limit to what we can ever hope to witness. Today we’re going to...

There are a lot of ways to get around in space, from using plain old sunlight to making super-hot plasma. We’ve talked about a lot of propulsion methods over the years, and now, it’s time for some highlights!

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In which John Green, Hank Green, and Emily Graslie teach you about what happened in the Universe after the big bang. They'll teach you about cosmic background radiation, how a bunch of hydrogen and helium turned into stars, formed...

In which John Green, Hank Green, and Emily Graslie teach you about what happened in the Universe after the big bang. They'll teach you about cosmic background radiation, how a bunch of hydrogen and helium turned into stars, formed...

Why does the universe seem to be moving in one particular direction?

How do we know what the air is like on planets we haven't visited? This video explains how to see air from 150 light years away. Thanks to NASA's James Webb Space Telescope project at the Space Telescope Science Institute for supporting...

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. The end of humanity and the end of the universe.John and Hank Green will...

Hank talks about astrobiology - the study of and search for life in the universe off Earth. Right now, the field has more questions than answers, but all they all seek to answer that one fundamental query: are we alone in the universe?

If you thought a hot dog eating contest was impressive to complete, imagine if a black hole entered it! They eat up everything around them, including stars! But they’re not just gluttonous blobs of the universe. Like all things in space,...

We have been studying our home galaxy for years, but even though astronomy has come a long way, there is still a lot we don't know about the Milky Way.

It's been conjectured that the center of the Milky Way is swarming with tens of thousands of black holes. And now we've actually seen them.

The ground under our feet is constantly moving, and to measure these movements, researchers have turned to an unlikely helper: quasars that are millions of light-years away.

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. The end of humanity and the end of the universe.John and Hank Green will...

Today from SciShow World News Headquarters (Hank's office) - news about radiation risks, the most hi-def astronomy ever, and the truth about aquatic humanoids.

The rumors are true! There's an Earth-like planet orbiting our neighboring star!

Astrophysicist and TED Fellow Sarah Rugheimer searches for aliens -- but not the cartoony green kind. She's looking for extraterrestrial microbes by studying how these single-celled organisms emit gases, which could reveal evidence of...

We can get to Mars in 3 days, . . .sort of, maybe. In this episode of SciShow Space Reid Reimers explains the possibilities of photonic propulsion in use with space travel.