NOVA | April 2025

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk. Follow scientists as they search for new clues to how mammals moved from land into the sea to become the largest animals on Earth.
Giant fossils uncovered in the Sahara Desert reveal new secrets of how whales evolved.
Explore key military technologies in the American colonies’ fight for freedom.
How did a ragtag army defeat the most powerful army in the world to win American independence? Discover the key military technologies that helped propel the colonies to victory, from the Brown Bess musket to the world’s first military submarine.
Explore how experts try to tackle the twin threats of climate change and the threat of extinction. Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales.
Follow scientists in a quest to understand how complex forest ecosystems can help cool our planet.
In the Arctic, enormous releases of methane, a potent greenhouse gas, threaten the climate
Scientists investigate colossal explosions in Siberia and other evidence that rapidly melting soil in the Arctic is releasing vast amounts of methane, a potent greenhouse gas. What are the implications for our climate future?
This two-hour feature documentary traces the roots of systemic racism in our medical system and the biological impacts of discrimination on the body to understand why Black Americans experience such disproportionately poor health outcomes.