The telescope was built on Mt. Hopkins in Arizona. It started working in 1979, and performed well. Its mirrors were equal to a single 176-inch (4.5-meter) mirror. However, even with the help of computers, it was still challenging to make all the mirrors target the same spot and operate as one.
The spin room
In the 1980s, a new glassmaking technique arose at the University of Arizona that allowed for the creation of bigger mirrors than ever before. The MMT astronomers made a decision: they would replace the six mirrors with one, even larger, mirror.
The University of Arizona’s glassmaking technique melted, molded and spun the glass into shape inside a rotating furnace. The mold gave the disk a honeycomb-like structure that made it lightweight yet strong. The MMT installed the first, single, 12.5 foot (6.5-meter) mirror created with this technique in the telescope in 1999. The change more than doubled the telescope’s light-gathering power and allowed it to see an area of the sky 400 times larger than before.
Get to the root of it
So the "Multiple Mirror Telescope" no longer has the most accurate name. Yet thanks to the new mirror, it remains one of the best telescopes in the world.
Like the Keck telescopes, the MMT uses adaptive optics, a new technique that uses a shape-changing mirror to reduce the blurry view caused by Earth’s atmosphere. Unlike the Keck telescopes, however, which have an extra mirror, the MMT applied adaptive optics to its secondary mirror when it installed the technology in 2003.
Caroline Barban
in 2002.
biography
- Fred L. Whipple
- The father of cometary science was an astronomer of multiple talents.