GranTeCan telescope and zodiacal light. This telescope dome, on La Palma, the Canary Islands, houses the Gran Telescopio Canarias (GTC, or GranTeCan), a 10.4-metre reflecting telescope. It has been the world’s largest single-aperture optical telescope since it opened in 2009. Operated by institutions from Spain, the USA and Mexico, it is located at an altitude of 2267 metres. Zodiacal light is caused by reflection of the Sun’s light off tiny dust particles in the plane of the solar system. The light (extending up from the horizon) is very faint, and is only visible on very dark, moonless nights.
Zodiacal light appears along the zodiac above the western horizon after sunset and above the eastern horizon before sunrise. In northern latitudes, the glow is best seen in the spring as twilight ends and in the autumn as dawn begins.
