Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000. Perth became known worldwide as the ''City of Light'' when city residents lit their house lights and streetlights as American astronaut John Glenn passed overhead while orbiting the earth on Friendship 7 in 1962. The city repeated the act as Glenn passed overhead on the Space Shuttle in 1998. Perth is tied for eighth place in The Economist's 2011 list of the World's Most Livable Cities.