4th Grade

How did sailors long ago know how to get from here to there? They needed smarts, bravery, and tools of navigation! Many of the tools used then are still used in some form today. Modern technology allows...

Seismologists have an important job. These scientists study earthquakes. Why is it so important to study earthquakes? By studying quakes, seismologists can help protect people from injury and death. Learn...

Hundreds of years ago, the Inka Empire was the largest on Earth. The Inka were great builders, and created roads that helped the empire run smoothly. The most impressive part of the Inka roads were the...

Modern meteorologists put science to work to predict what the future holds. These predictions tell people how to dress for the day, or whether to pack an umbrella. But that's not all they do! They also track...

The first prosthetic devices consisted of wooden legs and hooks for hands. Today, many prostheses and bionics can do everything a natural limb can do--and more! Learn about inventions from the past that have...

Streams are an important part of our world. They are the source of drinking water for countless plants and animals. But many streams are eroding. In Maryland, there is a huge effort to restore Muddy Creek...

The Horten Ho 229 was an experimental German airplane created by the Nazis. They believed its innovative design would help them win the war. Although this experimental aircraft never worked as planned, it's still...

The Arctic ecosystem is changing. The temperature is getting warmer, and the polar ice is melting. Polar scientists from around the world study the Arctic because changes there affect the entire planet. What...

History is everywhere you look. But what happens when natural disasters threaten important artifacts? Learn about the methods that conservators use to save important cultural artifacts in places hit by...

Landsat satellites are the superheroes of space. They orbit Earth to get images. These images can help stop catastrophes, and solve great mysteries. From poisoned water to raging fires, Landsat sees it all...

Learn about the world of optics, where light bends to help us see the sights! Most of us rely on our eyes to see and understand the world. Yet, human eyes are far from perfect. Innovations such as glasses,...

Electric vehicles, or EVs, have been around for over 100 years. The first EV that people could buy went on sale in 1894. The "Electrobat" could go 25 miles on one battery charge. Today's EVs are light, speedy,...