Professor Lawrence Krauss and Professor Michio Kaku explain the physics behind the events in the first second of The Big Bang, events which range from the first fractions of a second after creation: The Plank Era.
Thanks to observations of galaxy redshifts, we can tell that the universe is EXPANDING! Knowing that the universe is expanding and how quickly its expanding also allows us to run the clock backwards 14 billion years to the way the universe began - with a bang.
For twenty years, NASA's Cassini spacecraft revealed the strange secrets of Saturn until it vaporized in its atmosphere in a blaze of glory. But today its legacy lives on, as fresh data from the probe helps scientists make brand-new discoveries.
Double stars are stars that appear to be near each other in the sky, but if they’re gravitationally bound together we call them binary stars. Many stars are actually part of binary or multiple systems. If they are close enough together they can actually touch other, merging into one peanut-shaped star. In some close binaries matter can flow from one star to the other, changing the way it ages. If one star is a white dwarf, this can cause periodic explosions, and possibly even lead to blowing up the entire star.
This is the story of the most extraordinary journey in human exploration, the Voyager space mission. In 1977 two unmanned spacecraft were launched by NASA, heading for distant worlds. It would be the first time any man-made object would ever visit the farthest planets of the solar system - Jupiter, Saturn, Neptune and Uranus. On the way the Voyagers would be bombarded by space dust, fried by radiation and discover many of the remarkable wonders of the solar system. Now, at the end of 2012, 35 years and 11 billion miles later, they are leaving the area of the sun's influence. As they journey out into the galaxy beyond they carry a message from Earth, a golden record bolted to the side of each craft describing our civilisation in case of discovery by another. This is the definitive account of the most intrepid explorers in Earth's history.
2012 • Astronomy
Today Phil helps keep you from ticking off an astronomer in your life by making sure you know the difference between a meteor, meteorite, and meteoroid. When the Earth plows through the stream emitted by a comet we get a meteor shower. Meteors burn up about 100 km above the Earth, but some survive to hit the ground. Most of these meteorites are rocky, some are metallic, and a few are a mix of the two. Very big meteorites can be a very big problem, but there are plans in the works to prevent us from going the way of the dinosaurs.