The University of Illinois at Urbana-Champaign is the oldest and largest campus in the University of Illinois system. The university, then called the Illinois Industrial University, opened for classes on March 2, 1868, as a result of the 1862 Morrill Act. The name was officially changed to the University of Illinois in 1885, to reflect the broader scope of class offerings. The name of the Urbana location within the larger University of Illinois system was changed again in 1982, to The University of Illinois at Urbana-Champaign. The university department of physics is ranked among the top ten programs in the nation, and is the site of the Department of Energy's Center for the Simulation of Advanced Rockets, programs in materials science and condensed matter physics research, the Frederick Seitz Materials Research Laboratory, the Micro and Nanotechnology Laboratory, and a national historic landmark astronomical observatory.