Robert E Wells

In this work about the water cycle, readers discover that the molecules in their glass of water may have once been part of a dinosaur watering hole.

An introduction to the life-sustaining properties of Earth.

"Have you ever wondered how the moon was formed or why it changes shape in the sky? The moon's story began 4.5 billion years ago, but it continues to affect everything we do today, from weather to timekeeping. Award-winning science author Robert E. Wells explains how and why the moon matters in our lives-and for the future of space exploration"--

"A blue whale is big -- it's the biggest animal alive! But a blue whale would look small sitting on top of a mountain. And though a mountain is large, it's no more than a pebble in relation to the whole earth. But the earth isn't the biggest thing there is either! You'll discover some big things, some bigger things, and something beyond measure -- something we can truly call the biggest thing there is!" -- Back cover.

Bengal tigers are an endangered species, due to many human-caused factors, such as poaching, habitat destruction, and global warming. In Robert Wells' signature style, this book explores these difficult topics in a child-friendly manner with endearing illustrations, and it gives kids ways they can help to save the tigers, too.

How do you lift a lion? With a machine that's big and powerful with clanking metal parts? There are machines like that. But, others have only a few moving parts. In fact, some machines are so simple that they don't seem like machines at all-like the wheel, the lever, and the pulley. These machines can make work easy, even if you're trying to lift a lion!

If medals were awarded to animals for living a long time, then a giant tortoise would certainly win one. Some giant tortoises have lived for more than 150 years! Still, there are things on this planet much older than giant tortoises. Some of the giant sequoia trees that grow in California would be more than 3,000 years old. But, the trees aren't that old compared to the Barringer Crater in Arizona-that was made about 49,000 years ago. And, it's almost...

Take a journey through the heart of the Amazon rain forest to discover why it's so important for life on Earth. Even though rain forests take up less than 10 percent of Earth's land, they are home to more than half the world's plants and animals. In this adventure, readers climb aboard a river boat and tour the Amazon with a local guide. Observe howler monkeys, harpy eagles, and other wildlife as you discover how the planet's largest tropical rain...

A tiny difference in your DNA makes you one of a kind. Inside every cell in the human body are tiny molecules that define all of a person's biological traits. Award-winning science author Robert E. Wells explores DNA with curiosity and awe, pairing thrilling facts with clear explanations. Our human DNA might be 99% the same, but that last 1% difference makes each person unique.