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.
The first episode of this series focuses on a subject that has fascinated scientists for hundreds of years - stars. Right now in the Universe's giant furnaces stars are being born. See how their creation changed the cosmos forever, leading to planets and life itself.
When Mars One invited citizens to journey to Mars, 200,000 people applied. The final 100 include a military jet pilot, an ER doctor, and an IT consultant -- all willing to leave their loved ones forever. They share a common dream -- and a willingness to endure almost unimaginable isolation.
Black holes! From Stephen Hawking to Interstellar, black holes are mammoths in the world of science AND sci-fi. But what exactly IS a black hole? Do events happen inside black holes? Are black holes really a hole? Are black holes really black?! Join Gabe on this week’s episode of PBS Space Time as he debunks popular black hole misconceptions, and rethinks what the term, ‘black hole’, even means. Thought you knew what a black hole was? Think again!
Today we are talking about the life -- and death -- of stars. Low mass stars live a long time, fusing all their hydrogen into helium over a trillion years. More massive stars like the Sun live shorter lives. They fuse hydrogen into helium, and eventually helium into carbon (and also some oxygen and neon). When this happens they expand, get brighter, and cool off, becoming red giants. They lose most of their mass, exposing their cores, and then cool off over many billions of years.
Beginning with the separation of the fuzzy thinking and pious fraud of astrology from the careful observations of astronomy, Sagan follows the development of astronomical observation. Beginning with constellations and ceremonial calendars (such as those of the Anasazi), the story moves to the debate between Earth and Sun-centered models: Ptolemy and the geocentric worldview, Copernicus' theory, the data-gathering of Tycho Brahe, and the achievements of Johannes Kepler (Kepler's laws of planetary motion and the first science-fiction novel).