On 5 July 2012, a plume of Antarctic air descended over the European Southern Observatory's Paranal site in Chile. The home of the Very Large Telescope, Paranal is 2635 m above sea level and is almost always one of the best sites in the world for optical and near-infrared astronomy.
But for the 12 hours when the cold front visited the site, the atmosphere became extraordinarily dry, making the skies even clearer than usual. The team of scientists who report on this unusual event, led by ESO's Florian Kerber, now wonder if astronomers could exploit events of this type to make the best possible infrared observations of objects in the wider universe.
They publish their results in the journal Monthly Notices of the Royal Astronomical Society.
During this fleeting period of super dry skies, astronomer and ESO Photo Ambassador Gabriel Brammer captured a remarkable panoramic image of the Paranal site.
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"An episode of extremely low precipitable water vapour over Paranal observatory", F. Kerber, R. R. Querel, R. Rondanelli, R. Hanuschik, M. van den Ancker, O. Cuevas, A. Smette, J. Smoker, T. Rose and H. Czekala, Monthly Notices of the Royal Astronomical Society. First published online: January 28, 2014 DOI: 10.1093/mnras/stt2404