Planets: From our Solar System to new Exoworlds (Free Astronomy Public Lectures)

Presented on 18 March 2016 by Elodie Thilliez and Matthew Agnew.The Solar system is a remarkable place filled with wonderfully varied worlds. Travelling outwards from the sun we first encounter the hellish, rocky bodies of Mercury and Venus, continue to the cooler, water bearing world of Earth and our close neighbour Mars. Beyond the asteroid belt we hit the majestic gas giants of Jupiter and Saturn and continuing on our voyage we finally reach the cold ice giants of Uranus and Neptune. The Solar system is our home and our starting point for understanding planetary systems and their architectures. Until the late 20th century these were the only planets known to us, however, in the last two decades, there has been enormous and rapid progress in the discovery and understanding of planets beyond our Solar system, dubbed Exoplanets. As we discover more and more of these exoplanets, and the planetary systems to which they belong, our understanding of planet formation and planetary architectures has changed and raised several questions. Where did these Jupiter-sized, gas giants orbiting their stars in as little as 3 days come from? What is a 'super Earth'? Will we find another habitable world? In this lecture we will answer some of these questions as we explore our very own Solar system, look at how we observe and discover Exoplanets, and examine how these other planetary systems differ to our own.