In 1972, the crew of Apollo 17 captured the iconic 'Blue Marble': the first photograph ever taken by an astronaut of the entire Earth. This photo had a profound effect on our perception of ourselves. Since then, Nasa has taken millions more. In this epic, powerful and revelatory documentary, a new generation of astronauts, including Tim Peake, use those images of the Earth from space to reveal the astonishing transformation humanity has wrought in the 45 years since 'Blue Marble'. Together, the astronauts provide an armchair tour of the change they've witnessed from orbit, as humankind etches our presence on the planet. Using stunning time-lapse sequences, the programme reveals how we are reshaping our world, for better and for worse: from the sprawling megacities of China to vast desert farms in the Middle East and from the melting snowcap of Kilimanjaro to giant solar arrays in Nevada.
Now that we’ve finished our tour of the planets, we’re headed back to the asteroid belt. Asteroids are chunks of rock, metal, or both that were once part of smallish planets but were destroyed after collisions. Most orbit the Sun between Mars and Jupiter, but some get near the Earth. The biggest, Ceres is far smaller than the Moon but still big enough to be round and have undergone differentiation.
Carl Sagan opens the program with a description of the cosmos and a "Spaceship of the Imagination" (shaped like a dandelion seed). The ship journeys through the universe's hundred billion galaxies, the Local Group, the Andromeda Galaxy, the Milky Way, the Orion Nebula, our Solar System, and finally the planet Earth. Eratosthenes' successful calculation of the circumference of Earth leads to a description of the ancient Library of Alexandria. Finally, the "Ages of Science" are described, before pulling back to the full span of the Cosmic Calendar. Note: This revised version of the series adds an introduction by Ann Druyan, in which she discusses some of the changes that occurred in the years after its broadcast.
Set to the words of Carl Sagan, Pale Blue Dot is an animation that situates human history against the tapestry of the cosmos. Using a eclectic combination of art styles woven seamlessly together through music and visuals, the animation seeks to remind us that regardless of our differences, we are one species living together on the planet we call Earth.
2015 • Astronomy
The US efforts to colonize the Moon will follow the Lunar Exploration Roadmap, laid out with events taking place over decades. Other countries have plans as well. How will robots be deployed to work on the Moon? At what stage will people inhabit the environment? What minerals will be harvested?
Today on Crash Course Astronomy, Phil dives into some very dark matters. The stuff we can actually observe in the universe isn’t all there is. Galaxies and other large structures in the universe are created and shifted by a force we detect mostly indirectly, by observing its impact: DARK MATTER.