Astronomy TodayMicrowave Telescopes |
What does a ground-based microwave telescope look like, and how does it work? |
Ground-based microwave telescopes that detect so-called “sub-millimeter” radiation generally look like small radio telescope dishes. They are usually much larger than visible light telescopes, however, and are very carefully constructed and have very sensitive equipment. Some examples are the Submillimeter Telescope (SMT) at the Mount Graham International Observatory in southeastern Arizona and several telescopes on Mauna Kea in Hawaii: the James Clerk Maxell Telescope (JCMT), the Caltech Submillimeter Observatory (CSO), and the Sub-Millimeter Array (SMA). The largest facility in the world capable of conducting submillimeter-wave astronomy is the Atacama Large Millimeter/Submillimeter Array (ALMA) on the Chajnantor plateau in Chile.
Cold and dry sites are the best places to put microwave telescopes, and the coldest and driest place on Earth is the South Pole. At the Center for Astrophysical Research in Antarctica (CARA), there are two microwave telescopes: the Antarctic Sub-millimeter Telescope and Remote Observatory (AST/RO) and the Cosmic Background Radiation Anisotropy (COBRA) experiment. These telescopes look somewhat different from microwave telescopes at other sites in order to adapt to the harsh environmental conditions at the pole.