Astronaut Mike Massimino reveals the answers to some of the greatest mysteries on the Red Planet. Using the most detailed survey of Mars ever created, he discovers the dark history of our closest neighbor.
Astronaut Mike Massimino reveals the mysterious secrets of Saturn and its rings; using the latest science from the Cassini mission, he explores the planet's giant icy geysers, powerful hurricanes, and moon that may be hiding extraterrestrial life.
2017 • Astronomy
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.
Forget the big bang. The real moment of creation was the Cosmic Dawn - the moment of first light. This is the scientific version of the story of Genesis. The big bang gets all the credit for creating our universe. But in fact, the universe it gave was dark and boring. There were no stars, no galaxies, just a vast, black fog of gas - the cosmic dark ages. But, after a hundred million years of nothing, came a dramatic moment of transformation - the Cosmic Dawn. It's the moment the first stars were born, the moment that lit up the Universe, and made the first structure and the first ingredients of life. This was the real moment of creation. Astronomers are now trying to witness the cosmic dawn. For the first time they have the tools to explore the very first stars of the universe and to tell the scientific story of our creation.