It's famously called the Final Frontier, and thanks to rapidly developing technology we now know more about the outer reaches of our galaxy than ever. But that leaves unknowns.
Does the universe have any limits? Are there any other earth-like planets out there? And the big one, are we alone?
Addressing the University of Melbourne recently, Britain's Astronomer Royal, Lord Martin Rees, reports on the latest research.
Lord Martin Rees
Martin Rees is Professor of Cosmology and Astrophysics and Master of Trinity College at the University of Cambridge. He holds the honorary title of Astronomer Royal and also Visiting Professor at Imperial College London and at Leicester University.
After studying at the University of Cambridge, he held post-doctoral positions in the UK and the USA, before becoming a professor at Sussex University. In 1973, he became a fellow of King's College and Plumian Professor of Astronomy and Experimental Philosophy at Cambridge (continuing in the latter post until 1991) and served for ten years as director of Cambridge's Institute of Astronomy. From 1992 to 2003 he was a Royal Society Research Professor. He was president of the Royal Society between 2005 and 2010 and Member of Council of the Royal Institution of Great Britain until 2010. In 2011, he was awarded the Templeton Prize.
Cosmologist Lord Martin Rees describes the two domains of physical science as an ouroboros: the microscopic, which obeys quantum laws, and the astronomical, which follows Einstein's relativity. He places humanity as the link between the two, a complex species that pertains to both.