What we don’t know about comets (almost anything)
Doctor Paul Francis
A few times every year, comets wander into our solar system, out from the vast darkness beyond Pluto. Where do they come from? And why do they come to visit us? We don’t know, though there are several wild theories, some involving vast rings containing trillions of orbiting ice-blocs, or whole families of planets hundreds of times further out than Pluto. I’ll review these mysteries, and the enduring puzzle of what might lurk in the vast, dark, unexplored reaches between Pluto and the nearest stars.
Dr Paul Francis is an astronomer at the ANU’s Mt Stromlo Observatory. His research interests include black holes, the formation of galaxies, and comets. Born in London, he studied at Cambridge, since when he has worked with NASA, at Steward Observatory in Arizona, at Melbourne Uni, and at the Gemini Observatories in Hawaii and Chile. He has won a number of prizes for science communication and teaching.