Plenty of animal eyes "glow" in the dark, but only one species has eyes that change color with the seasons.

Fluorescent molecules are useful for a lot more than just making you look cool at your local rave. Fluorescence turns out to be a kind of chemical superpower that lets us tackle all kinds of problems, from solving crimes to saving lives!

Paul Andersen describes how cell communication is used in both single-celled and multicellular organisms. He starts by describing the symbiotic relationship between the bobtail squid and the bacteria Vibrio fisheri. He explains how...

Nearly all life on Earth is ultimately powered by light. But many creatures have learned how to make their own. This week we investigate the beautiful phenomenon of bioluminescence. From blinking fireflies on summer nights to glowing...

Hank explains why scientists spend so much time and brain power making animals that glow. Well, the first thing is, they don't really glow. And the second thing is: Scientists are just like the rest of us in that they don't believe some...

We’ve done a surprising amount of exploration on Mars, from its atmosphere, to its surface, and miles deep into its canyons. But mapping its insides has been a quandary that we hadn’t been able to solve until last week!

Everyone is watching the sky during a solar eclipse, but but if you look down, you'll catch another kind of light show.

Ever wonder what it looks like from a birds-eye-view? Hank explains they see more than you think!

If you find a glowing rock, it probably doesn't mean you're the chosen one. If it's one of these five phenomena, it's quantum mechanics, not narrative significance.

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Of all the weird animals that exist in the world, platypuses are up there with the weirdest, and last year scientists discovered something even more peculiar about their fur: it glows! What may be even more strange, though, is how little...

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. They can glow on their own or reflect light from nearby stars. When they glow...

Sharks come in a lot of different shapes and sizes and many of them don't look like the ones you see in movies. Here are seven sharks that went down some decidedly strange evolutionary paths.

Hank discusses some of the recent developments in synthetic biology, and why some advocacy groups are calling for a moratorium on those developments.

We have new insights into the bizarre nature of lava planets, and the icy moon Europa may yet reveal some of her salty secrets.

Gamma-ray bursts are one of the biggest mysteries in modern astronomy, but the mystery began on accident, thanks to the Cold War!

Some are longer than a blue whale. Others are barely larger than a grain of sand. One species unleashes one of the most deadly venoms on earth; another holds a secret that's behind some of the greatest breakthroughs in biology. They've...

In a few special places around the world, the ocean lights up at night with countless tiny blue flashes thanks to some tiny organisms and science.

Join Hank Green as he explains why blacklights make some things glow!

In the Pacific Ocean, there lives a fish that's . . . a little different. Hank tells you all about the Pacific barreleye fish!

Learn all about the anglerfish! A creepy-looking, deep-sea-dwelling creature that glows!

There's still a lot we don't know about the moon!

In this episode we explain why fire is red, gas flames are blue, and why you're too cool to glow.

About 60 percent of the ocean is a cold, dark region that spans down to 11,000 meters. This zone is known as the deep ocean, and though it seems like an inhospitable and remote corner of the planet, it is actually one of the greatest...

Movies like Predator reveal how useful thermal imaging goggles can be, but why do hot objects give off infrared radiation to begin with?