Link of the Week - Gaia |
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This week's Link is the Gaia project - a global space astrometry mission. Its goal is to make the largest, most precise three-dimensional map of our galaxy by surveying an unprecedented number of stars, more than a billion. The data- handling is done with a combination of grid and cloud computing. Gaia will monitor each of its target stars about 70 times over a five-year period, precisely charting their positions, distances, movements and changes in brightness. It is expected to discover hundreds of thousands of new celestial objects, such as extra-solar planets and failed stars called brown dwarfs. Within our own solar system, Gaia should also identify tens of thousands of asteroids. Additional scientific benefits include detection and characterization of tens of thousands of extra-solar planetary systems, a comprehensive survey of objects ranging from huge numbers of minor bodies in our solar system, through galaxies in the nearby universe, to about 500,000 distant quasars. It will also provide stringent new tests of Albert Einstein's general relativity theory. Run by the European Space Agency (ESA), members of the Gaia Science Operations Development Team did an experiment in running their grid infrastructure in the Amazon EC2 Cloud - with good results, they say. Paul Parsons and Alfonso Olias of the ESA described their experience at a talk at the CloudComputing Expo Europe in March. "I think this use case might be relevant for the scientific community as it shows that grids and clouds can live together," commented Olias. It's the kind of project that works well via distributed computing, they say; to do just one pass through the data on a single processor would take 30 years (at the rate of 1 millisecond to process one image). But with distributed computing, several iterations could be done in a much shorter time. With the developed in-house distributed computing software, at current estimates the project could be done in 2 weeks, using the Astrometric Global Iterative Solution (AGIS) in the Amazon cloud. Details of what they did for this trial run is on their post at the Amazon AWS blog. They are writing an article about their marriage of grids and clouds for an upcoming issue of iSGTW. -Dan Drollette, iSGTW |