Hiding on the floor of Earth’s tropical oceans are magnificent and colorful coral reefs. (Hardcover, paperback and eBook now available!)

The sun, the center of the solar system, is so large that 1,300,000 Earths could fit inside.

The monarch butterfly you see fluttering across the grass may be on a thousand-mile journey to another part of the world. 

Are all snakes dangerous to humans?

Exploding stars, black holes, space pods and strange space sights are only some of the mysteries of the universe.

Every star you see in the night sky is a gigantic sun, and some are a lot bigger and hotter than our own sun.

How come Pluto is no longer considered a planet?

Ever wonder what makes the wind blow or where clouds come from or why it rains?

Volcanoes can erupt and send red-hot rocks and ash flying through the air for hundreds of miles around.

Earth is the only planet in our Solar System with water on its surface—more than 1.5 quintillion tons of water—and it’s constantly in motion.

Lightning strikes the earth more than a hundred times every second of every day of the year.

The gigantic swirling storms called hurricanes bring heavy rains, flooding, and destructive winds.

If there’s global warming, why is it snowing?

Earthquakes can be the most destructive disasters in nature, destroying whole cities and killing hundreds of thousands of people.

You breathe more than twenty thousand times each and every day of your life.

The human body is like a huge city, with millions of inhabitants called cells.

Does the eerie howling of a wolf mean that wolves are the treacherous and sly animals of legend?

The biggest animal that ever lived is the blue whale and its tongue weighs as much as an elephant. 

Are all spiders poisonous? 

Are all snakes dangerous to humans?

Some sharks can bite 300 times harder than a human, enough to cut through a thick piece of steel.

How does a Penguin identify its own chick from among the thousands that want to be fed? 

By the time you finish reading this sentence, your heart will have beaten up to 50 times.

Gorillas are big and fearsome-looking but are they really gentle animals that live in social groups—just like people.

Dolphins are perhaps the most intelligent, curious and mischievous animal in nature. Now available in paperback!

Can your dog identify you by how you smell? Now available for the iPad (in the iBook store) and the NookColor (Barnes & Noble.com)!

Take a trip to the outer edges of known space and beyond.

Can cats see in the dark? Now available for the iPad (in the iTunes/iBook store) and the NookColor (Barnes & Noble.com)!

How does your brain know what’s happening to your feet?