Comets--these celestial travelers have forever filled us with fear and wonder. Lurking in the furthest reaches of our solar system, they come close to Earth as they orbit our Sun.

Meteors, comets, and asteroids cross the solar system to offer clues about our planet and universe. Can they destroy civilizations? Did they wipe out the dinosaurs? Have they brought life to our planet? And when will the next one hit? Aided by elaborate animation and live-action footage, we learn what these mysterious space rocks really are and imagine what likely happened 65-million years ago, when an object plowed into the Yucatan Peninsula. We see how certain spectacular meteor falls advanced our understanding of what they are and the danger that they pose. We talk to leading experts--astronomers and geologists including David Levy and Carolyn Shoemaker, co-discoverers of the Shoemaker-Levy comet that fell into Jupiter in 1994. And we talk to NASA scientists about recent missions to asteroids and comets and speculate on ways to move Earth-threatening asteroids and comets out of our way. Because it isn't a question of if, but when the next deadly impact will take place.

Hitch a ride on the journey of a comet as it roars from the cold, dark outer reaches of the solar system to the fiery surface of the Sun.

At this very moment, celestial forces prowl the Universe and threaten man's very existence. They're asteroids and comets--and they've left their imprint on planet Earth, literally. Initially, they helped build planets through violent collisions. During this fiery bombardment period, they may have even seeded Earth with water and the building blocks for life. Since the turbulent formation of the solar system, these space rocks have continued to impact earth. Some have been so violent that they've led to mass extinctions events, including one that wiped out the dinosaur. What's more, radical new theories suggest that asteroid and comet dust harbor deadly viruses that may have triggered some of our worst pandemics. The possibility of future cosmic collisions remains a legitimate threat. Yet, despite their dangers, asteroids and comets may hold vital natural resources, which could actually preserve mankind.

Sixty-five million years ago an asteroid the size of Mt. Everest slammed into the earth near South America exploding with the force of a million nuclear bombs and unleashing the power of the sun. The entire biomass of the earth was set ablaze, the atmosphere was cooked, and millions of life forms were wiped from the planet. Watch as experts, using the latest in modern scientific technology, reconstruct the last moments on earth and recreate the day that earth faced an unimaginable assault from space.

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?

Comets--these celestial travelers have forever filled us with fear and wonder. Lurking in the furthest reaches of our solar system, they come close to Earth as they orbit our Sun.

Meteors, comets, and asteroids cross the solar system to offer clues about our planet and universe. Can they destroy civilizations? Did they wipe out the dinosaurs? Have they brought life to our planet? And when will the next one hit? Aided by elaborate animation and live-action footage, we learn what these mysterious space rocks really are and imagine what likely happened 65-million years ago, when an object plowed into the Yucatan Peninsula. We see how certain spectacular meteor falls advanced our understanding of what they are and the danger that they pose. We talk to leading experts--astronomers and geologists including David Levy and Carolyn Shoemaker, co-discoverers of the Shoemaker-Levy comet that fell into Jupiter in 1994. And we talk to NASA scientists about recent missions to asteroids and comets and speculate on ways to move Earth-threatening asteroids and comets out of our way. Because it isn't a question of if, but when the next deadly impact will take place.

Hitch a ride on the journey of a comet as it roars from the cold, dark outer reaches of the solar system to the fiery surface of the Sun.

At this very moment, celestial forces prowl the Universe and threaten man's very existence. They're asteroids and comets--and they've left their imprint on planet Earth, literally. Initially, they helped build planets through violent collisions. During this fiery bombardment period, they may have even seeded Earth with water and the building blocks for life. Since the turbulent formation of the solar system, these space rocks have continued to impact earth. Some have been so violent that they've led to mass extinctions events, including one that wiped out the dinosaur. What's more, radical new theories suggest that asteroid and comet dust harbor deadly viruses that may have triggered some of our worst pandemics. The possibility of future cosmic collisions remains a legitimate threat. Yet, despite their dangers, asteroids and comets may hold vital natural resources, which could actually preserve mankind.

Sixty-five million years ago an asteroid the size of Mt. Everest slammed into the earth near South America exploding with the force of a million nuclear bombs and unleashing the power of the sun. The entire biomass of the earth was set ablaze, the atmosphere was cooked, and millions of life forms were wiped from the planet. Watch as experts, using the latest in modern scientific technology, reconstruct the last moments on earth and recreate the day that earth faced an unimaginable assault from space.

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?

Comets--these celestial travelers have forever filled us with fear and wonder. Lurking in the furthest reaches of our solar system, they come close to Earth as they orbit our Sun.

Meteors, comets, and asteroids cross the solar system to offer clues about our planet and universe. Can they destroy civilizations? Did they wipe out the dinosaurs? Have they brought life to our planet? And when will the next one hit? Aided by elaborate animation and live-action footage, we learn what these mysterious space rocks really are and imagine what likely happened 65-million years ago, when an object plowed into the Yucatan Peninsula. We see how certain spectacular meteor falls advanced our understanding of what they are and the danger that they pose. We talk to leading experts--astronomers and geologists including David Levy and Carolyn Shoemaker, co-discoverers of the Shoemaker-Levy comet that fell into Jupiter in 1994. And we talk to NASA scientists about recent missions to asteroids and comets and speculate on ways to move Earth-threatening asteroids and comets out of our way. Because it isn't a question of if, but when the next deadly impact will take place.

Hitch a ride on the journey of a comet as it roars from the cold, dark outer reaches of the solar system to the fiery surface of the Sun.

At this very moment, celestial forces prowl the Universe and threaten man's very existence. They're asteroids and comets--and they've left their imprint on planet Earth, literally. Initially, they helped build planets through violent collisions. During this fiery bombardment period, they may have even seeded Earth with water and the building blocks for life. Since the turbulent formation of the solar system, these space rocks have continued to impact earth. Some have been so violent that they've led to mass extinctions events, including one that wiped out the dinosaur. What's more, radical new theories suggest that asteroid and comet dust harbor deadly viruses that may have triggered some of our worst pandemics. The possibility of future cosmic collisions remains a legitimate threat. Yet, despite their dangers, asteroids and comets may hold vital natural resources, which could actually preserve mankind.

Sixty-five million years ago an asteroid the size of Mt. Everest slammed into the earth near South America exploding with the force of a million nuclear bombs and unleashing the power of the sun. The entire biomass of the earth was set ablaze, the atmosphere was cooked, and millions of life forms were wiped from the planet. Watch as experts, using the latest in modern scientific technology, reconstruct the last moments on earth and recreate the day that earth faced an unimaginable assault from space.

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?