The Hubble Space Telescope, together with many other space-based and ground-based observatories, have given us a much clearer picture than we ever had before of the universe we live in. We now know not only that other planetary systems are quite common, but that the cosmic expansion is accelerating. We know the age of the universe, its geometry, and its composition. Observations of stars start to reach the level of detail previously characterizing only solar physics. A general picture of the formation of structure in the universe, and many clues for how galaxies form and evolve, start to emerge. We know that supermassive black holes reside at the centers of most galaxies. This is, however, far from marking the end of HST's contributions. The recent installation of the Advanced Camera for Surveys, and the two future (currently planned for 2004) instruments, the Cosmic Origins Spectrograph (COS) and the Wide Field Camera 3 (equipped with an infrared channel), promise that the coming seven years will be at least as exciting as the first thirteen were.
Acknowledgments
This review has benefited from discussions with more colleagues than I can practically thank here. I would like, however, to extend special thanks to John Bally, Stefano Casertano, Mark Dickinson, Gia Dvali, Harry Ferguson, Andy Fruchter, Mauro Giavalisco, Ron Gilliland, Andy Ingersoll, Ken Lanzetta, Nino Panagia, Saul Perelmutter, Adam Riess, Kailash Sahu, Rachel Somerville, Massimo Stiavelli, Roeland van der Marel, and Alex Vilinkin for very helpful discussions.