Asteroid - Oct. 2006
Will a doomsday rock the size of the Rose Bowl hit Earth in 2036?
Bird Brains - July 2008
Clues to the origins of human language are turning up in the brains of birds.
Booming Sands - Jan. 2005
Scientists look into a generations-old conundrum: how and why do certain sand dunes produce mysterious noises?
Capturing Carbon - July 2008
An 8th-grader's science project prompts her scientist father to develop a new way to pull excess CO2 out of the atmosphere.
Diamond Factory - June 2009
Visit a laboratory where entrepreneurs are growing perfectly pure diamonds.
Dinosaur Plague - July 2009
Insects caught in amber spark a controversial theory about what killed the dinosaurs.
Emergence - July 2007
How does the "intelligence" of an ant colony or the stock market arise out of the simple actions of its members?
Fastest Glacier - July 2005
A glacier moving way too fast reveals how unpredictable the effects of global warming can be.
First Primates - July 2008
Our most distant primate ancestors, which took the stage shortly after the dinosaurs left it, were tree-dwellers the size of mice.
Frozen Frogs - Apr. 2005
The common wood frog freezes solid every winter and then, come spring, defrosts and mates.
Hurricane Katrina - Oct. 2005
Our January 2005 segment on New Orleans' risk from hurricanes proved sadly prescient, as this update reveals.
Hurricanes - Jan. 2005
Predicting a hurricane's intensity is notoriously difficult, but new tools may make it easier.
Ivory-Billed Woodpecker - Jan. 2006
An enchanting bird believed extinct mysteriously reappears ... maybe.
Leeches - July 2008
A century after falling out of favor among doctors, medicinal leeches are back in hospitals, sucking away on patients' wounds.
Lightning - Oct. 2005
Experts still aren't sure what triggers it, but they suspect cosmic rays from outer space.
Little People of Flores - Apr. 2005
The remains of three-foot-tall humans are discovered on a remote Indonesian island.
Mammoth Mystery - July 2008
A pair of mammoth skeletons is found locked together by their tusks. What happened?
Mass Extinction - Nov. 2006
What caused the mother of all extinctions 250 million years ago?
Maya - Jan. 2007
NASA archeologists use satellites to pinpoint ancient ruins buried deep in the jungle.
Papyrus - Nov. 2006
Scraps of writings from a garbage dump in ancient Egypt reveal what life was like 2,000 years ago.
Profile: Julie Schablitsky - July 2007
Meet an archeologist who is helping to rewrite the history of the Old West.
Profile: Edith Widder - July 2008
Meet a marine biologist and explorer who has engineered new ways to spy on deep-sea creatures.
The Search for ET - July 2008
Astronomers have their radio telescopes tuned to receive signals from alien worlds. But is anybody out there?
Secrets in the Salt - July 2009
Salt deposits that formed 250 million years ago hold tantalizing hints of early life.
Smart Sea Lions and Talking Walruses - July 2009
Marine mammals are wowing researchers with more than just circus tricks.
Space Storms - July 2008
Behind the dazzling display of the aurora borealis are space storms that could turn the lights off here on Earth.
Stronger Hurricanes - Jan. 2006
Is global warming making hurricanes more intense?
T. Rex - Apr. 2005
An astonishing adolescent growth spurt accounts for T. rex's enormous size.
T. Rex Blood? - July 2007
Preserved soft tissue, including possible blood vessels and red blood cells, are turning up in dinosaur fossils.