Public Talk

8pm, Tuesday, 4 June 2013

Victoria Convention Centre

720 Douglas Street Victoria BC


HABITABLE WORLDS: The Search Continues

We search for planets like Earth because we are interested in finding life elsewhere. One could counter than this view is myopic – that life might be silicon based or floating in methane clouds on worlds that are very different from our planet. We would have a difficult time recognizing life that is so fundamentally different from anything on Earth. Surely, our best shot is to search for what we know: carbon-based life inhabiting rocky planets awash with oceans of water. This search must focus on nearby stars because even familiar signatures of life, like oxygen rich atmospheres, will be easier to detect on planets orbiting the closest stars.

Twenty years ago, we did not know if exoplanets were rare or common. Today, we know that most stars harbor small rocky planets like the Earth. Paradoxically, we have not yet carried out a sensitive search for these planets around the nearest stars. As this search begins in the next few years, we will learn if life is rare or common.

Debra Fischer is a Professor of Astronomy at Yale University who began hunting for exoplanets in 1997 by measuring tiny wobbles in the velocities of stars. She has discovered hundreds of exoplanets, including the first known multiple planet system in 1999. Her worked helped to advance understanding of planet formation by quantifying correlations between the planets and the chemical composition of host stars.

From 2003 – 2008, she led an international consortium to carry out a search for planets around metal-rich stars; that project alone detected more than 50 new extrasolar planets. Some of the planets that Fischer has found transit in front of their host stars; for these lucky cases, the size and density of the planets can be measured and reveal an incredible diversity in the interior structure of unseen planets orbiting stars that are hundreds of light years away. She is the principal investigator for CHIRON, a high-resolution spectrometer commissioned in Chile at Cerra Tololo Observatory in June 2012 that is breaking the precision records in the search for exoplanets. She and her team are now at work designing a next generation instrument to find 100 Earths.