Grades 9-12

The Enigma of High Energy Cosmic Rays

Article

The Enigma of High Energy Cosmic Rays

In 1912, Viktor Hess took to the sky in a hot-air balloon and discovered a radioactive energy now called “cosmic rays.” Travel to Argentina to see how scientists now hope to discover at long last where the highest-energy cosmic rays are coming from.

Essay: Stars in Exquisite Accuracy

Essay

Essay: Stars in Exquisite Accuracy

There’s only one star that astronomers have a firm grasp on: the Sun. Fundamental facts about other stars remain elusive. Find out how a powerful interferometer atop Mount Wilson in Southern California hopes to change that.

Species and Sprawl: Humans

Article

Species and Sprawl: Humans

Sprawl is affecting Homo sapiens as it does many other species: it alters our habitat, hampers our mobility, and diminishes odds for survival.

Species and Sprawl: Wood Turtles

Article

Species and Sprawl: Wood Turtles

See how scientists are using radio telemetry to gain a clearer picture of how much and what kind of space wood turtles need to survive.

Species and Sprawl: Yellow Starthistle

Article

Species and Sprawl: Yellow Starthistle

Seeds can't move by themselves, so they rely on moving things to give them a lift. Discover how cars are taking homespun seed dispersal mechanisms to a new level.

Species and Sprawl: Mountain Lions

Article

Species and Sprawl: Mountain Lions

What's the animal-friendly antidote to California's urbanization? Some believe the solution is to make the corridors between disparate patches of wild lands truly useable by many different species.

Science Stays Alert, Part I: Birds Under Scrutiny

Article

Science Stays Alert, Part I: Birds Under Scrutiny

In a handful of cases, humans have contracted H5N1 from birds and then passed the virus to other humans. Even so, doctors and scientists are taking great pains to prepare for the possibility of such a pandemic.

Elephants Return to the Forest

Article

Elephants Return to the Forest

Unlike most zoo-raised or domestic species, Asian elephants have never been selectively bred, so they remain genetically wild. See how this helps with forest reintroduction efforts. 

Article: The Wild Horse, Yesterday and Today

Article

Article: The Wild Horse, Yesterday and Today

Modern horses are part of the family Equidae. The fossil history of Equidae is well documented, but new evidence about its evolutionary history — and new interpretations of it — continue to accumulate. 

For Educators: The World's Largest Dinosaurs

Curriculum Collection

For Educators: The World's Largest Dinosaurs

For 140 million years giant dinosaurs called sauropods roamed Earth. Help students investigate the success of the largest land animals ever with this practical and printable exhibition guide for educators.

Interactive

Interactive: Watch a Glacier Melt

Qori Kalis is the largest outlet glacier of Peru's Quelccaya ice cap. See firsthand how it (like all tropical glacier ice) is melting because of global warming.

Interactive

Observing Jellies

Long ago, people studied jellies by peering over the side of a boat and drawing the creatures as they bobbed nearby. See how much has changed since the 1800s.

Interactive

Interactive: How Far is Far?

This interactive explains how astronomers measure the properties of light from faraway space objects to calculate their distance from Earth. Users click through a series of pages that explain the concepts step-by-step with illustrations and animations.

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