In Kitt Peak, Arizona, lies one of the most amazing telescopes in the world and also the largest solar instrument on the planet. The McMath-Pierce Solar Telescope is a rather odd-looking facility that towers 30 metres (100 feet) high, with a diagonal shaft stretching 60 metres (200 feet) used to make detailed observations of the Sun. The primary mirror of the telescope, which is 1.6 metres (5.2 feet) wide, is located underground at the end of the shaft through which light travels. The structure was built back in 1962 and since then has continually been used to view features on the Sun, such as sunspots, in exceptional detail. Its many discoveries include the detection of water and isotopic helium in the Sun and the first high-resolution images down to just 1.6 microns. To make uninterrupted observations, the huge structure is able to withstand winds of 40 kilometres (25 miles) an hour without moving more than 0.4 millimetres (1/60th of an inch).
Image Credit: John Owens