The Marianas Trench is the deepest place on earth, deeper than Mt. Everest is high. the trench is where the ocean floor disappears into the center of the earth. the pressures at this depth are 17 times greater than what it takes to crush a nuclear submarine. Only two men have ever been down the Trench, fewer than have set foot on the moon. Follow the daring missions into the abyss and explore the extraordinary geology that has created this deep scar along the ocean floor.

The Grand Canyon is nearly 300 miles long and over a mile deep. You could stack four Empire State buildings one on top of the other and they still wouldn't reach the lip of the Canyon. As vast tectonic plates clash and grind against one another a giant plateau has been pushed up over a mile in the air. the Colorado river, flowing from high in the Rockies and carrying a thick load of sediment, has carved an amazing canyon in the rising plateau.

From Alaska to New Mexico, the Rockies are one of the great mountain belts of the world--caused by tectonic forces of the Pacific Plate pushing against the North American continent. They have formed as the earth's continental crust has been shortened under pressure--by around 1 inch a year. What's more, they are still rising and they are still young in geologic terms: when the dinosaurs roamed the Earth they had not even started to form.

The single longest linear feature on Earth--the "Ring of Fire" circles almost the entire Pacific. It is a ring of active volcanoes from White Island just north of New Zealand, through the South China seas, Japan, Kamchatka, the Aleutians, the Cascades and down through the Andes. Almost 25,000 miles long, it is one of the most awesome sights on Earth.

The Atacama desert is considered the driest place on Earth. Since human records of the area began, some places have never received rain. But the records don't stop there--the Atacama is also the oldest desert in the world, and recently it has been dated to an amazing 150 million years old. Other research shows that the surface of this desert is also incredibly ancient, with boulders lying there that have not moved for over 23 million years--more than 50 times longer than it's taken for our human species to evolve. the soil is so dry, it has been used as a test bed for the Mars rovers. And though the desert was once thought to be completely lifeless, strange bacteria discovered there have given scientists new hope that they might find life on the red planet. Atacama is also home to the largest copper mine in the world. Inspect the riddle of the Atacama and uncover how this extraordinarily dry landscape was created.

In the remote wastes of Siberia buried under snow are the remains of one of the greatest catastrophes that the Earth has endured. 250 million years ago, huge volumes of lava spewed out onto the surface--so much that it would have buried the whole of Texas under one mile of lava. At first the temperature dipped but then the greenhouse gases that escaped from the depressurized lava caused a massive global warming. It wreaked havoc and 95% of the species on Earth became extinct. Yet life hung on and in time this disaster paved the way for the next great phase of life on earth--the age of the dinosaurs.

The Sierra Nevada, North America's highest mountain range, contains one of the most awe-inspiring geological features on the planet: Yosemite Valley. Walled by sheer 3,000-foot granite cliffs and made from one of the toughest rocks on earth, it is home to the mighty El Capitan and iconic Half Dome. Yet how this extraordinary valley formed has been the subject of controversy for over 100 years. Was it carved by gigantic glaciers or a cataclysmic rifting of the Earth?

These giant mountain-sized boulders from space have wrought death and destruction throughout the millennia but until recently geologists could find no evidence that they had actually struck the earth. Follow the remarkable detective story that begins at Meteor Crater in Arizona as mining engineers desperately try to unearth the billion dollar iron boulder they thought was lying there. It's a detective story that also uncovers immense riches; the world's biggest nickel deposit in Sudbury, Canada, vast oil reserves in the Gulf of Mexico and a gold mine in South Africa--all the result of asteroid impacts. Evidence is also unearthed of violent impacts that decimated some of the first people to live in America. What clues do asteroids, and their smaller cousins, meteorites, hold in the formation of the early Earth and perhaps life itself?