Take a look back with us at the biggest science stories of 2017.

Crows can remember the face of their captors—even after generations.

Watch astonishing tests of avian aptitude: parrots that can plan for the future, jackdaws that can “read” human faces, and crows that can solve multi-step puzzles with tools like pebbles, sticks, and hooks. Could these just be clever tricks, based on instinct or triggered by subtle cues from their human handlers?

Here are three mind-blowing ideas for what may be inside a black hole.

As a kid, Janna Levin loved cosmology—now, she’s an award-winning author and host of “Black Hole Apocalypse”

Chung-Pei Ma is both a gifted violinist and one of the world’s foremost black hole hunters.

NOVA has teamed up with Cook's Illustrated to cook up a recipe for stars and black holes.

Andrea Ghez asks the ultimate question: Is there a supermassive black hole at the center of our galaxy?

As a child, theoretical astrophysicist Priya Natarajan loved atlas. As an adult, she maps the cosmos.

Black holes are the most enigmatic and exotic objects in the universe. They’re also the most powerful, with gravity so strong it can actually trap light. And they’re destructive. Anything that falls into them vanishes…gone forever. But now, astrophysicists are realizing that black holes may be essential to understanding how our universe unfolded—possibly leading to life on Earth and us.

Black holes are the most enigmatic and exotic objects in the universe. They’re also the most powerful, with gravity so strong it can actually trap light. And they’re destructive. Anything that falls into them vanishes…gone forever. But now, astrophysicists are realizing that black holes may be essential to understanding how our universe unfolded—possibly leading to life on Earth and us.

Black holes are mind-blowing. Discover the FOUR types of black holes that exist in the cosmos.

66 million years ago, a seven-mile-wide asteroid collided with Earth, triggering a chain of events that coincide with the end of the dinosaurs. But experts have long debated exactly what happened when the asteroid struck and how the giant beasts met their end. Now, scientists have uncovered compelling new clues about the catastrophe.

Anywhere information goes, even in your mind, energy goes with it—bottle up that energy and it has mass.

Can states, cities, and companies fulfill US obligations to the Paris Accord on their own?

Most wild turkeys are timid. But if one gets aggressive, what do you do?

Cosmic particles reveal a previously hidden void in the Great Pyramid of Khufu in Egypt.

What makes a brain or machine conscious? This theory is beginning to provide some answers.

If a neuroscientist designed a haunted house, would you dare to enter?

From lobster claws and dog teeth to bee stings and snake fangs, every creature depends on a weapon. But some are armed to extremes that make no practical sense—whether it’s bull elks with giant 40-pound antler racks or tiny rhinoceros beetles with horns bigger than their body. What explains giant tusks, horns, and claws that can slow an animal down and even impair health and nutrition?