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Science In Action: 06/10/2011

06/10/2011

BBC World Service - Science In Action, 06/10/2011

A new hole in the ozone layer over the Arctic was caused by our cold winter last year.

A new hole in the ozone layer over the Arctic was caused by our cold winter last year; Water in our oceans may have been delivered by comets; Largest radio telescope ALMA opens; Nobel Prizes awarded.

Arctic Ozone Hole
Scientists have discovered a hole in the ozone layer, and say that CFC gases are to blame. This isn’t a headline from over 20 years ago. It’s the findings of brand new research published in the journal Nature. This time the hole is above the Arctic, not the Antarctic, and it could mean that people in the Northern Hemisphere are exposed to high levels of UV radiation, which causes sunburn and even skin cancer.  
Dr Markus Rex from the Alfred Wegener Institute in Germany explains that CFCs are still hanging around in high layers of the atmosphere, and during extremely low temperatures periods like the cold winter we had last, they are more aggressive and more ozone gets destroyed, creating a hole.

Water from Comets
The oceans on earth may have come from space. Astronomers in Germany have identified a new cosmic source for the substance that covers around 70% of the planet. Over four billion years ago the Earth was formed violently and was extremely hot for a long time afterwards.  Any water there would have been evaporated instantly, so the origin of our deep oceans has been something of a mystery.  Scientists think that the water was delivered later, by comets or asteroids smashing into the planet.  By measuring what type of water was found in comets, looking at how much deuterium, the heavy form of hydrogen, was present in the water, missions in the past more or less ruled out these icy bodies as the source of out oceans, looking instead to more rocky asteroids for their delivery.  But new measurements carried out by Paul Hartogh and other researchers at the Max Planck Institute in Germany have used the Herschel Space Telescope to identify a new family of comets near to Jupiter that have the same type of water as is found on Earth, and therefore could be the source of all the water in our oceans.

ALMA Telescope
The world’s most powerful radio telescope has begun its scientific operation.  The Atacama Large Millimetre/Sub-millimetre Array, ALMA has begun operations in Chile this week, starting one of the largest ground-based astronomy projects of the next decade.  It is hoped that the project will be able to see far enough into space and time to be able to view the formation of some of the first stars in the universe.  The telescope consists of an array of 50 giant antennae on top of one of the highest plateaus in the Chilean Atacama desert, and is an impressive sight.  BBC Science correspondent Pallab Ghosh went to see it first hand, and describes the extreme conditions and scientific goals.

Nobel Prizes
Each year since 1901, Nobel Prizes have been awarded for advances in Medicine or Physiology, Physics, Chemistry, Literature, Economic Sciences, and Peace.  This year the science awards have been particularly interesting.  On Monday, the award for Medicine went to Bruce Beutler and James Hoffmann ‘for their discoveries concerning the activation of innate immunity and to Ralph Steinman ‘for his discovery of the dendritic cell and its role in adaptive immunity’.  The Physics prize was awarded on Tuesday to Saul Perlmetter, Adam Reiss and Brian Schmidt ‘for the discovery of the accelerating expansion of the Universe through observations of distant supernovae’.  The Chemistry prize, awarded on Wednesday, was awarded to Dan Schechtman ‘for the discovery of quasicrystals’.  Most people may have never heard of quasicrystals, but Ronan McGrath of the Surface Science Research Centre at the University of Liverpool explains how Schechtman’s controversial discovery represented a rare revolution in the field of science.

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