In the dark depths of the oceans, nearly 90 percent of all species shine from within. Whether it’s to scare off predators, fish for prey or lure a mate, the language of light is everywhere in the ocean depths, where most creatures flash, sparkle, shimmer, or simply glow.

A newly discovered 500-year-old wreck offers vital clues to this momentous innovation.

Against all odds, African-American chemist Percy Julian became one of the great scientists of the 20th century. The grandson of Alabama slaves, Percy Julian met with every possible barrier in a deeply segregated America. He was a man of genius, devotion, and determination. As a black man he was also an outsider, fighting to make a place for himself in a profession and country divided by bigotry—a man who would eventually find freedom in the laboratory. By the time of his death, Julian had risen to the highest levels of scientific and personal achievement, overcoming countless obstacles to become a world-class scientist, a self-made millionaire, and a civil-rights pioneer.

Join the mission as the New Horizons spacecraft attempts to fly by NASA's most distant target yet. Since it explored Pluto in 2015, New Horizons is zooming toward Ultima Thule, an object four billion miles from Earth.

More than 2,000 years ago, the thriving city of Petra rose up in the bone-dry desert of what is now Jordan. An oasis of culture and abundance, the city was built by wealthy merchants who carved spectacular temple-tombs into its cliffs, raised a monumental Great Temple and devised an ingenious system that channeled water to vineyards, bathhouses, fountains and pools. But following a catastrophic earthquake and a slump in its desert trade routes, Petra’s unique culture faded and was lost to most of the world for nearly 1,000 years. Now, in a daring experiment, an archaeologist and sculptors team up to carve an iconic temple-tomb to find out how the ancient people of Petra built their city of stone.

NOVA Can We Cool the Planet? documents how, as global temperatures rise, scientists are exploring geoengineering solutions to solve the problem – from planting trees to sucking carbon out of the air to physically blocking out sunlight. And if any of these work, what are the risks of engineering Earth's climate?

NOVA Touching the Asteroid documents the mission of NASA spacecraft OSIRIS-REx as it attempts to reach out and grab a piece of an asteroid named Bennu and bring it back to Earth. The OSIRIS-REx team has just three chances to extend the spacecraft’s specialized arm, touch down for five seconds, and collect material from the surface of Bennu. NOVA takes us inside the mission that, if successful, could give scientists new insight into Earth’s origins.

Just as writing changed the course of human history, the evolution of paper and printing revolutionized the spread of information. The printing press kicked off the Industrial Revolution that fast-tracked us to the current digital age. But as the 4,000-year-old tradition of penmanship falls out of favor, should we consider what might be lost in this pursuit of ever more efficient communication?

Where would we be without the world’s alphabets? Writing has played a vital role in the expansion and domination of cultures throughout history. But researchers are only now uncovering the origin story to our own alphabet, which may have gotten its beginnings in a turquoise mine 4,000 years ago. From the shape of the letter A to the role of writing in trade and storytelling, discover how the written word shaped civilization itself.

Scientists race to understand and defeat the coronavirus behind the COVID-19 pandemic. The coronavirus SARS-CoV-2 has upended life as we know it in a matter of mere months. But at the same time, an unprecedented global effort to understand and contain the virus—and find a treatment for the disease it causes—is underway. Join the doctors on the front lines of the fight against COVID-19 as they strategize to stop the spread, and meet the researchers racing to develop treatments and vaccines. Along the way, discover how this devastating disease emerged, what it does to the human body, and why it exploded into a pandemic.