Albert Lin travels to Petra, Jordan, to discover the origins of the famous city; he learns that it was built by the Nabataeans and reveals that the ancient city of Petra was part of a much larger network than he had ever imagined.
Life on Earth starts as single-cell bacteria and stays like that for two billion years; then, a miraculous event transforms Earth into a complex interconnected web based on a competition for food.
The epic story of Earth's battle with the sun and how life thrives against all odds; hurling devastating particles and deadly radiation at Earth, the sun is the big boss of the solar system; without several shields, life on Earth wouldn't survive.
After 665 weightless days in space, astronaut Peggy Whitson smashes through the atmosphere on her last journey home to planet Earth; with her first steps back on land, she encounters fresh air, blue skies, warm sun, and gravity.
Ever since life emerged, microbes, plants and animals have sculpted the planet's surface and atmosphere in the strangest of ways: from rocks to rivers, life has crafted everything that makes Earth so special.
The forays of the Slough Creek pack into Druid territory result in an epic battle; the Druid wolves dominate the Lamar Valley area in the lead-up to the fight.