Prof. Paul Murdin OBE is Senior Fellow at the Institute of Astronomy at the University of Cambridge, and had entitled his talk
Prof. Paul Murdin OBE is Senior Fellow at the Institute of Astronomy at the University of Cambridge, and had entitled his talk Extraterrestrial water and planetary landscapes.
As everyone learned in school chemistry, water is H2O, its molecule made of hydrogen and oxygen. These are two of the most common elements in the universe, and water molecules are abundant in space. The water on Earth was, mostly, made in space, and came here when the sun and the planets were made by gas condensing from interstellar space, 4.6 billion years ago. Comets are watery-rocky icebergs left over from this time. Other planets have water, unless they are too near their sun and too hot, like the planet Mercury. The planet Mars used to have water in abundance and its landscape shows dry lakes and river valleys, water-deposited strata exposed on the faces of cliffs, and the scoring of drainage beds by the most massive flood in the history of the solar system. Most of its water evaporated 2 billion years ago in a global catastrophe of climate change, but Mars still has icy polar caps and seeping springs, as well as hoar frost in the mornings. Pluto and some satellites of Jupiter and Saturn are covered in icy rocks, and one is entirely covered in ice sheets, floating on a deep ocean containing more water than there is on Earth. The strangest satellite of Saturn is Titan, with rain, lakes and rivers – an entire hydrological landscape. Only its ice floes are water-ice (H2O): the landscape is familiar because so similar to ours, but it is sculpted from liquid methane. The search for extraterrestrial life is intimately connected to the search for water on other planets, and Titan exemplifies an earth-like planet in its pre-biotic aspects.
I will illustrate this tour of watery worlds beyond our own with pictures obtained by space probes, landers and rovers, the proxy humans that we have sent to explore our solar system on our behalf, to display to us what we would like to see for ourselves, tourism that, as yet, we cannot accomplish.
(Thursday) 14:45 - 15:35
B: Studio 1
Dartington Hall, Totnes, Devon TQ9 6EN