Earth Science & Climate

What Is an Umbra? The Darkest Part of a Shadow

What Does Coal Ash Look Like? From Powder to Sludge

How Dark Does It Get in Sweden?

What Does Heliocentric Mean? The Sun-Centered Model

Does the Universe Rotate? What the Evidence Shows

What Is Decomposed Granite Used For?

What Is It Called When Snow and Ice Come Crashing Down a Slope?

How Much Does Topsoil Cost Per Cubic Yard?

How Many Seismograms Are Required to Locate an Earthquake?

When Was the Last Time Mt. Hood Erupted?

How Much Does 2 Cubic Feet of Soil Weigh?

Is Arizona Water Hard or Soft?

How Were the Earth’s Layers Formed?

Does Lake Superior Freeze? The Science of Its Ice

Are Fossil Fuels Actually Fossils?

How Common Are EF5 Tornadoes? Statistics & Rarity

Why Is the Bering Sea So Rough?

What Is a Mineral? A Simple Explanation for Kids

What Is Planetary Differentiation?

Why Are Deserts in Danger of Flash Floods?