Assertion: telescope | /r/CapableOf | observe at the 21 cm
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text: The telescope bowl was originally going to have a wire mesh surface to observe at wavelengths between 1 and 10 meters (3.2 and 32 feet), so frequencies between 30 and 300 MHz; this was changed to a steel surface so that the telescope could observe at the 21 cm (8 in) hydrogen line, which was discovered in 1951.