ATLAS is one of two general-purpose detectors at the LHC. You can think of it like a huge camera taking pictures 40 million times per second of the microscopic explosions created by smashing two protons together. These pictures result in nearly one petabyte of information every second, only a fraction of which is saved on computer disks to be analyzed by scientists like me.

More than 2900 scientists from 172 institutes in 37 countries work on the ATLAS experiment (December 2009).