Take an exhilarating, unprecedented exploration of the seven most amazing wonders of our solar system. Our virtual tour begins with a trip to Enceladus, one of Saturn's outer moons, where icy geysers spout from its surface. Then venture to Saturn's famous rings, which contain mountain ranges that rival the Alps. Next dive into the eye of the biggest storm in the solar system--Jupiter's Great Red Spot. Soar through the Asteroid Belt, containing millions of leftover rocks from the formation of the solar system. Trek up Mount Olympus, the largest volcano, located on Mars. Have a close encounter with the searing surface of the Sun, and finish the journey by exploring our home planet Earth.

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.

Asteroids strike, planets collide, black holes blast out death rays, volcanoes erupt and ice engulfs the planet. These are the universe's weapons of extinction. They've happened before - wiping out entire species, and they will happen again. Are we next?

Follow astronaut Scott Kelly’s record-breaking 12-month mission on the International Space Station, from launch to landing, as NASA charts the effects of long-duration spaceflight. A Russian Soyuz spacecraft carried Scott Kelly of NASA and Mikhail Kornienko of Roscosmos to the space station for the longest space mission ever assigned to a NASA astronaut". The expedition provided important insights into operational and scientific areas in human research in space and on Earth. Integrated scientific investigations between NASA and Roscosmos will combine resources to improve data sharing among space medical and human research communities, as well as help inform current assessments of crew performance and health and better determine and validate countermeasures to reduce the risks associated with future exploration as NASA plans for missions around the moon, to an asteroid and eventually to Mars.

Sagan discusses comets and asteroids as planetary impactors, giving recent examples of the Tunguska event and a lunar impact described by Canterbury monks in 1178. It moves to a description of the environment of Venus, from the previous fantastic theories of people such as Immanuel Velikovsky to the information gained by the Venera landers and its implications for Earth's greenhouse effect. The Cosmos Update highlights the connection to global warming.

This episode explores the palaeogeography of Earth over millions of years, and its impact on the development of life on the planet. Tyson starts by explaining that the lignin-rich trees evolved in the Carboniferous era about 300 million ago, then explains on the nature of plate tectonics that would shape the landmasses of the world and the asteroid impact that initiated the Cretaceous–Paleogene extinction event, leaving small mammals as the dominate species on earth. Earth's landmasses are expected to change in the future and postulates what may be the next great extinction event.