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.

In a collision with Earth, asteroids could set off raging fires and colossal tidal waves. Yet some asteroids are loaded with billions of dollars’ worth of elements. Will asteroids turn out to be our economic salvation — or instruments of extinction?

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

Can new emission-free electric planes replace our airliners?

Hear the personal stories of those struggling with infertility.

Women make up less than a quarter of STEM professionals in the United States, but a growing group of researchers is writing a new chapter for women scientists, exposing longstanding discrimination. NOVA Picture a Scientist introduces female scientists who provide new perspectives on how to make science itself more diverse, equitable and open to all.

NOVA Looking for Life on Mars follows NASA’s Mars 2020 Mission, perhaps the most ambitious hunt ever for signs of life on Mars. NOVA reports on NASA’s successful attempt to lower the Perseverance Rover into the red planet’s rocky Jezero Crater, home to a dried-up river delta scientists think could have harbored life.

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.