Animals
Around the world, birds are in crisis
Human activities around the world are threatening bird species. Numbers of even some of the most common species are starting to fall.
Word of the Week
Health & Medicine
Scientists Say: Apoptosis
When it’s time for cells to die, they need to do it carefully, so they don’t harm other cells.
Explainers
Earth
Explainer: Our atmosphere — layer by layer
Earth’s five layers extend from the ground up and into outer space. Each has its own distinct features and serves as the site of different activities and phenomena.
Analyze This!
Oceans
Analyze This: Shipwrecks provide a home for bottom-dwelling fish
Fish have found a habitat in a submarine and freighter that sunk to the seafloor during World War II.
What's Hot
Secrets to Better Learning
Watch This
How physics lets a toy boat float upside down
Buoyancy’s upward force keeps objects afloat even in unusual conditions.
