Astronomy

The black hole at the centre of the Milky Way is getting ready to feast. A gas cloud three times the size of our planet has strayed within the gravitational reach of our nearest supermassive black hole. And across the globe, telescopes are being trained on the heart of our Milky Way galaxy, some 27,000 light years from Earth, in the expectation of observing this unique cosmic spectacle. For cosmic detectives across the Earth, it is a unique opportunity. For the first time in the history of science, they hope to observe in action the awesome spectacle of a feeding supermassive black hole.

What sort of alien civilizations might exist in the vastness of space? Terra is the fictional world imagined in Episode 4, a planet nine billion years old, twice as old as Earth. Old enough that a truly advanced intelligence could evolve. It was once a fertile world, now it is barren. But life can still thrive here in artificial domes. Over time, they've evolved not to need their bodies. They exist only as neural tissue. They never age, they never die. They're monitored and maintained by robots.
If alien civilizations are statistically so likely, why haven't astronomers found any sign of them? Where is everyone? Every time we look at an individual star, that's like dropping a bucket in the ocean. We're going to have to look at a lot of stars and to search through a lot of data until we find the clue that leads us to another civilization.

Do other worlds tremble and heave with geological life? On Mars, we found a volcano to dwarf Mount Everest. On the moons of the giants our understanding of volcanoes was changed forever.

Have planet hunters finally found proof of other Earth like worlds? Astronomers have now discovered over two hundred alien worlds, beyond our solar system, that were unknown just a decade ago. Discover planets that rage with fiery hurricanes and bizarre planets covered by water so dense that it forms a kind of hot ice. Among these weird worlds, Earth actually seems like the oddball.

Carl Sagan teaches students in a classroom in his childhood home in Brooklyn, New York, which leads into a history of the different mythologies about stars and the gradual revelation of their true nature. In ancient Greece, some philosophers (Aristarchus of Samos, Thales of Miletus, Anaximander, Theodorus of Samos, Empedocles, Democritus) freely pursue scientific knowledge, while others (Plato, Aristotle, and the Pythagoreans) advocate slavery and epistemic secrecy.

How did the universe come to be? Thanks to a series of discoveries, our most powerful space missions have unravelled 13.8 billion years of cosmic evolution and revealed the story of our universe from its birth all the way to the arrival of our nascent civilization. Our guide on this odyssey back to the dawn of time is light. Telescopes are time machines - by looking out into the distant universe, they open a window to the past. One telescope more than any other has helped us journey through the history of the universe: NASA’s Hubble Space Telescope. Remarkably, Hubble has even found one of the first galaxies ever to exist in the universe, which was born some 13.4 billion years ago. It's a discovery that hints at the beginnings of our own Milky Way. Vivid CGI brings this ancient galaxy to life, allowing us to witness for ourselves the first dawn. It was the beginning of a relationship between stars and planets that would, on a faraway world, lead to the origin of life - and ultimately to us.
Hubble’s incredible discoveries have allowed scientists to piece together much of our cosmic story, but it cannot take us back to the most important moment in history: the Big Bang. For decades, the moment the universe began was the subject of pure speculation, but by combining astronomy and cosmology, scientists have finally found a way to put their theories to the test and study the momentous events that took place during the Big Bang. They can do this because the European Space Agency’s Planck space telescope has seen the afterglow of the Big Bang itself – something we call the Cosmic Microwave Background. The unparalleled detail Planck gave us has helped confirm something remarkable: the Big Bang may not be the beginning. There was a time before the dawn – a place beyond anything we can comprehend. Professor Brian Cox transports us back to the fraction of a second before the Big Bang, when the seeds of our universe were planted.