Scientists discover evidence for the key ingredients for life on Saturn's moon Enceladus.

Comets carrying chemicals necessary for life may have come to Earth billions of years ago.

Human papillomavirus, or HPV, can cause cervical cancer. Bhutan is the first developing country to welcome the widespread vaccination of girls against HPV, and cervical cancer rates have dropped. Some countries have resisted the vaccine, but in Bhutan even the royal princess is onboard.

The world can be a dangerous place, full of foes large and little. Take deadly infectious diseases. Host David Pogue considers a new kind of vaccine that might save millions of lives, while eliminating the need for refrigeration and scary needles.

Dorothy Roseman describes her close encounters with vaccine-preventable diseases.

Science shows it’s a small world after all—and nature’s networks follow a similar pattern.

Diseases that were largely eradicated in the United States a generation ago—whooping cough, measles, mumps—are returning, in part because nervous parents are skipping their children's shots. NOVA takes viewers around the world to track epidemics, explore the science behind vaccinations, hear from parents wrestling with vaccine-related questions, and shed light on the risks of opting out.

Diseases that were largely eradicated in the United States a generation ago—whooping cough, measles, mumps—are returning, in part because nervous parents are skipping their children's shots. NOVA takes viewers around the world to track epidemics, explore the science behind vaccinations, hear from parents wrestling with vaccine-related questions, and shed light on the risks of opting out.

Three physicists untie a 150-year-old tangle of a puzzle.

A city-wide competition shaped the career of the architect behind Florence’s famous dome.

Did a lethal plague kill thousands in ancient Rome? Centuries-old DNA may hold the answer.

A chance discover during a game of rugby led Dutch POWs to an ingenious WWII jailbreak.

The Allies used silent wooden gliders to get behind enemy lines before the D-Day landings.

A crack team rebuilds a glider that POWs hoped to catapult off the top of Colditz Castle. Airing May 14, 2014 at 9 pm on PBS

Marine biologist Patrick Rice is using rare earth elements to repel sharks.

In World War I, the Germans used cow guts to construct their deadly Zeppelins.

A "cosmic fingerprint" reveals the universe’s beginning and gravity's microscopic secrets.

Explore the social lives of some of the smartest animals on the planet. Airing April 23, 2014 at 9 pm on PBS

What would life on a red dwarf planet look like?

How do dogs, sharks, dolphins, or birds experience the world? Airing April 16, 2014 at 9 pm on PBS