From its highest mountains to its deepest oceans, our world has challenged explorers of every generation to reach further and seek what lies beyond the horizon. Century upon century, the lure of the unknown has taken humans to every corner of the globe and it has given us a view of Earth that our ancestors could barely imagine. Now, the drive to explore is leading us upward and outward - off our own planet and out into the solar system where a host of alien worlds offers us vast new terrains to uncover. We roam this territory today, not with our material bodies, but with our robot surrogates, which we have flung through the brutal vacuum and sent plunging into conditions more extreme than any astronaut could endure. Today we see the sun, moon and planets with penetrating clarity - not through human eyes, but through the eyes of the intrepid machines that are blazing a trail for us across the solar system. Their cameras have become our windows onto a bold new adventure.