The 6.5 metre Multiple Mirror Telescope (MMT) is a joint venture between the Smithsonian Institution and the University of Arizona. The MMT is located on the summit of Mt. Hopkins, the second highest peak in the Santa Rita Range, approximately 55 kilometres (30 miles) south of Tucson, Arizona.

Some facts about the telescope:

• Observatory location: Mount Hopkins, Arizona, USA
• Height above sea level: 2,606 metres (8,550 feet)
• Moving Mass: 150 metric tonnes (each unit)
• Mirror diameter: 6.5 metres (each unit)

Although called the Multiple Mirror Telescope, the name is now historical. Before 1999, the telescope consisted of six small mirrors which collected the light and focused it towards the telescopes instruments. After 1999, those mirrors were replaced with a single 6.5 m diameter mirror, collecting twice as much light as before. Despite the change in mirror, the old MMT name stuck.