Chris Martin: Exploring the Ultraviolet Universe

Each band of the electromagnetic spectrum is tuned to individual physical processes that uncover the astrophysical mechanisms behind the Universe we see — planets, stars, galaxies — and the Universe we cannot see, consisting of dark matter and dark energy. The space ultraviolet, visible only above the Earth's atmosphere from rockets and satellites, has given us a dramatic new perspective on the formation of cosmic structure. Only in the last decade has it become technologically possible to map the UV sky, and in the process we have made "expected" and truly "unexpected" discoveries about stars and galaxies.

Martin will discuss some of the many results of the Galaxy Evolution Explorer, a NASA Explorer satellite mapping the UV sky. These range from remarkable clouds of gas and dust around nearby stars to the history of star formation that converted primordial gas into stars in galaxies as the Universe evolved. He will touch upon some of the challenges we faced in launching the mission, and will talk about how future UV missions that we are developing will allow us to map a hitherto invisible component of the Universe, the intergalactic medium that was the birthplace of galaxies.

The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope observing galaxies in ultraviolet light across 10 billion years of cosmic history. GALEX's observations are telling scientists how galaxies, the basic structures of our Universe, evolve and change. Additionally, with its mission to see 80% of the way back to the Big Bang, GALEX observations are investigating the causes of star formation during a period when most of the stars and elements we see today had their origins.

Chris Martin, Professor of Physics at Caltech, is the principal investigator for the GALEX mission, a partnership between the Caltech and NASA's Jet Propulsion Laboratory (JPL) with universities, science institutes, laboratories, and commercial technology providers from around the world.

Please Note: This event will be digitally recorded and made available for viewing on the Caltech Theater site. Many past Watson Lectures are available for viewing online on the Caltech Theater site, and are available for purchase: DVD Order Form (PDF)