From the mission that saw Pluto for the first time to the Mars rovers, a new breed of explorers are risking their careers, and even their lives, to lead humanity to worlds we have never seen and tackle the mysteries of life itself.
Tornadoes, hurricanes, snowstorms, lightning and floods – for us these destructive forces are symptoms of Earth's creative energy. The weather on Earth is one of the drivers for life and even the most violent and destructive storms create new opportunities for life to flourish. In our quest to discover if we are alone in the universe, we have recently hit upon a surprising new approach — we shouldn't just look for worlds, we should look for weather. What is true of Earth could also be true of other planets throughout the whole universe. Across the immense distances of space, find chaotic weather — find that megastorm — and maybe we will find alien life.
The fourth planet from the sun and the outermost of the terrestrial planets, Mars has long been a popular spot for missions and imagination. Phil walks you through the planet's topography, core, and features. We'll take a look back to Mars's past and makes predictions for its future, including the possibilities for human life.
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.