While refracting and reflecting telescopes use different means of collecting light, the same principle applies to both—the bigger the aperture, the more light collected.

When you think of your family's traditions and beliefs, what special objects come to mind? Would the meaning and value of these objects be clear to someone from another family or culture?

In outer space, you might not recognize the Big Dipper. The stars that form this constellation exist in 3-D not 2-D—so the star pattern changes with your viewpoint. Take another look at the Big Dipper.

Ankylosaurus, Barosaurus, Coelophysis—add to your dinosaur vocabulary with these 12 illustrations. Soon you'll be able to spot a Pachycephalosaurus from across the room.

Now you can gaze at your favorite museum diorama anytime you want, night or day. Grab your crayons, and create a shoe-box replica of A Wading Bird Rookery, The Olympic Rain Forest, or A Giant Cactus Forest.

Discover how artists bring dinosaur skeletons to life with skin, feathers, and other features. Then try to create your own lifelike Velociraptor from a skeletal drawing.

When you've been alive for less than a decade, how in the world do you grasp geologic time? Start with a 100-inch-long roll of adding machine tape and measure out Earth's past.

More than 35 million years ago, horses thrived in wet forests. Take a close look at horse fossils to see what paleontologists can learn from studying an extinct animal’s bones and teeth.

The most common fossils are bones and teeth, but not all fossils are body parts. Explore the wide-ranging evidence of ancient life that scientists use to understand Earth's prehistoric past.

How many times would your footprint fit into that of a large dinosaur? Could all of your classmate's feet fill up the small crater? Find out with this personalized look at the 35-ton Apatosaur.