Picturing the universe in high definition

Wait until the largest survey telescope ever built starts producing data to figure out how to process and analyze an anticipated 100 million CDs worth, and you’re too late.

The data deluge when the Large Synoptic Survey Telescope (LSST) comes online near the end of the decade will create a flood so huge catching up would be impossible in the lifetime of any researcher involved in the project.

DiaGrid, which can make nearly tens of thousands of computer processors available for research projects, is giving scientists a head start on figuring out how to deal with all this data. Purdue physics Professor John Peterson and his students simulate — photon by photon — the pictures the new telescope will produce from billions of stars and galaxies.  

“We have to do simulations now to make sure we can even analyze this much data,” Peterson says.

To do those simulations, they’re running trillions of computations on DiaGrid.

“Basically, every computer can work on some small part of the sky and just simulate the protons from that small part of the sky,” Peterson says. “With (DiaGrid) you can for periods of time use thousands of machines.”

Peterson and his students have been able to divide the task and parcel it out so the computers in DiaGrid are working on more than one simulated image, and hence multiple parts of the sky, at a time. They also factor in details such as distortion from the distance the light travels on its trip to Earth, the effects of the atmosphere and the idiosyncrasies of the telescope itself.

The simulated images go to scientists writing the software that will be used to analyze the real thing when the LSST is up and running.

Scientists predict that the LSST may lead to the discovery of about 3 billion new galaxies, 1,000 times more than are known already. The survey telescope also is expected to enable measurements that could help explain the mysterious phenomena dark energy and dark matter, which are central to remaining questions about the origins and fabric of the universe.

Dr. John Peterson
Associate Professor of Physics
Purdue University