How do we see far off galaxies, discover new planets and stars and study the secrets hidden in space? Riley goes to Chile to visit the world's largest, most advanced optical combined telescope, which provides astrophysicists with some of the answers to questions about the Big Bang, the nature of matter and the origins of the universe. But at the moment the results are not so clear. The mirror that focuses on stars from millions of light years away needs cleaning. It is a 23-ton mirror shaped like a contact lens. They load it, truck it, polish it, give it a new coating, then put it back into its home.