Picture of the Week
The kind of matter and energy we can see and touch – whether it is in the form of atoms and molecules, or heat and light, only forms a tiny proportion of the content of the Universe, only about 5%. Over a quarter is dark matter, which is totally invisible but whose gravitational attraction can be detected; while over two thirds is dark energy, a force that pushes the Universe to expand ever faster.
UCL Chemistry-led research on the Origin of Water on Earth
30 November 2010
UCL Chemistry-led research on the Origin of Water on Earth, published as front cover in RSC Chemical Communications, was featured in the New Scientist and selected as an RSC Chemical Science Highlight
Computational research led by Nora de Leeuw has validated a new theory on the source of terrestrial water.
The origin of water on our planet is not only of interest for our understanding of the evolution of our own planet and life thereon, but even more so for the increasing exploration of other planets within our solar system and the discovery of potential planetary systems in other galaxies.
Having spent half a life-time teaching his students the accepted versions of the origin of our planetary water, which increasingly did not fit the available evidence, Mike Drake at the University of Arizona suggested an alternative hypothesis, where water was already present at the surfaces of interstellar dust grains, when they accreted to form our planet. Although this hypothesis fitted with all available evidence, it would only work if the adsorption of water to the dust grains was sufficiently strong to survive the harsh conditions in the accretion disk.
Computer simulations by De Leeuw and colleagues in UCL, Arizona and Muenster on the chemisorption of water to surfaces of the olivine mineral, which is ubiquitous in interstellar dust clouds, show that the kind of highly fractal surfaces found on the interstellar dust grains are indeed suitable for the strong retention of water under the extreme temperatures and pressure conditions prevalent in the accretion disk during planetary formation. This work thus provides very strong evidence that the new hypothesis as to the delivery of water is correct; water was indeed present at the birth of our planet Earth rather than a late-comer once the planet had been formed.
The full paper is available on the RSC Chemical Science website at http://pubs.rsc.org/en/Content/ArticleLanding/2010/CC/C0CC02312D, whereas the New Scientist article is available on http://www.newscientist.com/article/mg20827853.800-earth-may-have-had-water-from-day-one.html and the RSC ‘Chemical Science Highlight’ can be found here http://www.rsc.org/Publishing/ChemScience/Volume/2010/11/Earth_water.asp
Page last modified on 30 nov 10 14:58