What are the latest discoveries in the deadly world of asteroids? Will a recently returned Japanese spacecraft become the first to bring an asteroid sample back to our planet? What would happen to America's East Coast if the massive asteroid impact that helped form Chesapeake Bay 35 million years ago struck today? And why did President Barack Obama choose an asteroid as the destination for the next great manned mission into space? Learning about these huge space rocks isn't just about science, it's about survival.

Find out what is being done to prevent the end of the world from threats from outer space such as comets and asteroids. Also discussed are apocalyptic scenarios.

Take a tour through the Art Gallery of the Galaxy and view what are considered the "crown jewels" of the heavens. Nebulas are mysterious clouds of gas that aren't classified as stars, planets, moons or asteroids. Astronomers use the most sophisticated techniques to view them since they are practically invisible to the naked eye. Nothing less than stunning, nebulas glow, reflect or obscure the galaxy's light with amazing swirls of color. Nebulas mark the regions where the nothingness of space first coalesces, where stars are born and where stars die. Cutting-edge computer graphics are used to bring the universe down to earth.

Right now cosmic forces prowl the universe and threaten man's very existence. They're asteroids and comets; they've left their imprint on planet Earth, literally. Initially helping to 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, including one that wiped out the dinosaur. New theories suggest that asteroid and comet dust harbour deadly viruses that may have triggered some of our worst pandemics. The possibility of future collisions remains a legitimate threat yet despite their dangers, asteroids and comets may hold vital natural resources, which could actually preserve

It sounds like a Hollywood blockbuster: a deadly asteroid is on a collision course with Earth. But in reality, it's only a matter of time before a giant space rock threatens to wipe out civilization. An asteroid took out the dinosaurs sixty-five million years ago. Are we next? This episode analyzes the threat and explores the many ways--from a nuclear bomb to ingenious new technology--that experts are proposing to stop Armageddon

This episode is centered around how science, in particular the work of Clair Patterson (voiced in animated sequences by Richard Gere[33]) in the middle of the 20th century, has been able to determine the age of the Earth. Tyson first describes how the Earth was formed from the coalescence of matter some millions of years after the formation of the Sun, and while scientists can examine the formations in rock stratum to date some geological events, these can only trace back millions of years. Instead, scientists have used the debris from meteor impacts, such as the Meteor Crater in Arizona, knowing that the material from such meteors coming from the asteroid belt would have been made at the same time as the Earth. Patterson also examined the levels of lead in the common environment and in deeper parts of the oceans and Antarctic ice, showing that lead had only been brought to the surface in recent times. He would discover that the higher levels of lead were from the use of tetraethyllead in leaded gasoline resulting in government-mandated restrictions on the use of lead.