In a single century, the salmon population of Washington State's Elwha River shrunk by more than 99 percent. What caused this dramatic decline, and what can be done to turn it around?

Humans have harmlessly harvested coral reefs for thousands—or even hundreds of thousands—of years. So why has our behavior in recent years suddenly put reefs at risk?

How much can you reduce your carbon dioxide emissions? Is it worth it? Learn how simple choices multiplied by everyone in your community can make a big difference.

Meet the little dinosaurs of Ghost Ranch. Investigate evolution and the loss of flight in dinosaurs and birds. And dig deep into the lives of dinosaurs with these recommended reads.

Launched on December 14, 2009, the WISE space telescope is helping scientists create a Digital Universe 3-D Atlas. Take a look at WISE and the data it is capturing.

Scientists have been studying brown dwarfs, or failed stars, for nearly a century. What have they learned? And what answers are they still seeking about these objects stuck somewhere between stars and planets?

Two teams working independently in 1998 came to the same conclusion: An invisible force, one that seems to act opposite gravity, is separating the matter in space at an increasing pace. Find out more about their “jaw-dropping” discovery.

If LIGO regularly registers gravitational waves, it will more than vindicate Einstein. The observatory may help answer pressing questions about the cosmos’s biggest mysteries, among them black holes, dark matter, and the Big Bang.

Anything with an accelerating mass has a gravitational effect — an atomic bomb, a spinning aircraft carrier, even you. Learn more about these ripples in space and how LIGO is designed to capture the biggest gravitational waves.