Prof. James Kasting

(Penn State University)

5:30pm Thursday 8th December

Christopher Ingold LT, Chemistry dept., UCL

Public lecture, followed by wine reception and book signing

In their 2000 book, Rare Earth, Peter Ward and Don Brownlee argue that complex life (i.e., animal life) is rare in our galaxy for a variety of reasons, some of which are based on the idea that habitable planets are themselves rare. Possible reasons for this include: 1) Plate tectonics (possibly necessary to stabilize planetary climates) is rare; 2) large moons (possibly necessary to stabilize planetary obliquities) are rare; 3) magnetic fields (possibly necessary to retain atmospheres) are rare; 4) the Sun is anomalously metal-rich; 5) Jupiter-sized outer planets (possibly necessary to protect the Earth from frequent large impacts) are rare. In my talk, I will review these Rare Earth arguments and show that most, or all, of them are less troubling than Ward and Brownlee supposed. Despite this, perhaps there are other factors that could make habitable planets scarce. But this should not discourage us from building the types of large space telescopes required to actually answer this question.

James Kasting is a geoscientist and Distinguished Professor at Penn State University. He is a leading expert in the field of planetary habitability, and what sort of world you might need to support life. Prof. Kasting is also a gifted popular science writer, and his most recent book, 'How to Find a Habitable Planet', will be available after the event.

[for further information, please email Dr. Lewis Dartnell -  l.dartnell@ucl.ac.uk]