Chemicals from the Earth's atmosphere are making their way down to the planet. Not in spaceships, but in rain. The acid rain can infiltrate ground water, lakes, and streams. How does acid rain affect aquatic ecosystems?

Everything on our planet is linked by a giant recycling system called the biogeochemical cycle. How our planet recycles and reuses everything we need to support life is explained by making a miniature biosphere in this lab. You will also...

Earth's atmosphere, the ocean of air that blankets the planet, is mostly nitrogen and oxygen, with small amounts of other gases. How much oxygen is present in air at sea level? Is air high up in the Appalachians or Rockies? Atop Mount...

How do astronomers collect stardust? They design and build satellites that are launched into space to collect particles on specially designed panels. Satellites can be sent to orbit around an object of interest: a planet, moon, or comet....

Our home, Earth, is a living planet. Earthquakes and volcanic eruptions are proof that the geological forces that shaped our planet and created the land masses are ongoing. An amazing example of geologic activity that is less damaging is...

Pizza, milk shakes, and ice cream sundaes all contain dairy products, therefore they cannot be eaten by the majority of people around the world. Dairy products contain the sugar molecule lactose, and the majority of people on the planet...