Nova

Egyptian desert fossils reveal clues to the evolution of the biggest animals on Earth.

Egyptian desert fossils reveal clues to the evolution of the biggest animals on Earth.

Egyptian desert fossils reveal clues to the evolution of the biggest animals on Earth.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

Egyptian desert fossils reveal clues to the evolution of the biggest animals on Earth.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

Egyptian desert fossils reveal clues to the evolution of the biggest animals on Earth.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

Deep in the Cambodian jungle lie the ruins of Angkor, a marvel of urban engineering and seat of the once-mighty Khmer Empire.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

A spectacular fossil graveyard reveals a 43-million-year-old whale that had four legs and could walk.

Join Sir David Attenborough on a unique excavation of a site in southwest England with rare traces of ancient mammoths and Neanderthals.

Join Sir David Attenborough on a unique excavation of a site in southwest England with rare traces of ancient mammoths and Neanderthals.

Join Sir David Attenborough on a unique excavation of a site in southwest England with rare traces of ancient mammoths and Neanderthals.

Jupiter's massive gravitational force made it a wrecking ball when it barreled through the early solar system.

Join Sir David Attenborough on a unique excavation of a site in southwest England with rare traces of ancient mammoths and Neanderthals.

Join Sir David Attenborough on a unique excavation of a site in southwest England with rare traces of ancient mammoths and Neanderthals.

Join Sir David Attenborough on a unique excavation of a site in southwest England with rare traces of ancient mammoths and Neanderthals.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

Wielding chainsaws to extract fossils frozen into the permafrost and flying drones to map thousands of footprints, intrepid paleontologists discover that dinosaurs thrived in the unlikeliest of places -- the cold and dark of the Arctic Circle.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

What would the restoration of Earth's forests mean in the fight against climate change? Follow researchers around the globe as they race to understand how nature processes and responds to carbon on the largest scales and how microorganisms, plants, animals, and humans combine to sustain healthy ecosystems.

Archaeologists investigate dozens of strange Stone Age megastructures in the Arabian desert.

Archaeologists investigate dozens of strange Stone Age megastructures in the Arabian desert.

Archaeologists investigate dozens of strange Stone Age megastructures in the Arabian desert.

Archaeologists investigate dozens of strange Stone Age megastructures in the Arabian desert.

Archaeologists investigate dozens of strange Stone Age megastructures in the Arabian desert.

Archaeologists investigate dozens of strange Stone Age megastructures in the Arabian desert.

Archaeologists investigate dozens of strange Stone Age megastructures in the Arabian desert.

Archaeologists investigate dozens of strange Stone Age megastructures in the Arabian desert.

Archaeologists investigate dozens of strange Stone Age megastructures in the Arabian desert.

Archaeologists investigate dozens of strange Stone Age megastructures in the Arabian desert.

Archaeologists investigate dozens of strange Stone Age megastructures in the Arabian desert.