For many years our place in the universe was the subject of theologians and philosophers, not scientists, but in 1960 one man changed all that. Dr Frank Drake was one of the leading lights in the new science of radio astronomy when he did something that was not only revolutionary, but could have cost him his career. Working at the National Radio Astronomy Observatory in Greenback in Virginia, he pointed one of their new 25-metre radio telescopes at a star called Tau Ceti twelve light years from earth, hoping for signs of extraterrestrial intelligence.
Last week we covered multiple star systems, but what if we added thousands or even millions of stars to the mix? A star cluster. There are different kinds of clusters, though. Open clusters contain hundreds or thousands of stars held together by gravity. They’re young, and evaporate over time, their stars let loose to roam space freely. Globular clusters, on the other hand, are larger, have hundreds of thousands of stars, and are more spherical. They’re very old, a significant fraction of the age of the Universe itself, and that means their stars have less heavy elements in them, are redder, and probably don’t have planets (though we’re not really sure).
Professor Brian Cox explores the powerhouse of them all, the sun. In India he witnesses a total solar eclipse and in Norway, he watches the battle between the sun's wind and Earth, as the night sky glows with the northern lights. Beyond earth, the solar wind continues, creating dazzling aurora on other planets.
The Sun created our Solar System and in a fit of cosmic cannibalism will engulf and destroy it. However, our Solar System will see many changes before the light of our star goes out. So, what will be happening with the planets over the next four billion years, before the Sun swallows us and them?
The universe is unbelievably big – trillions of stars and even more planets. Soo… there just has to be life out there, right? But where is it? Why don’t we see any aliens? Where are they? And more importantly, what does this tell us about our own fate in this gigantic and scary universe?