If you ever wondered how scientists clean giant telescopes on Earth, wonder no more. This video from the European Southern Observatory shows just what it's like to clean and recoat one of the 8.2-meter main mirrors of observatory's Very Large Telescope in Chile's Atacama Desert.
"Every night the huge mirrors are exposed to the atmosphere whilst uncovered during observing sessions," ESO officials said in a video description. "They gradually accumulate dust and other pollutants that reduce their reflectivity, making them less effective at capturing faint light from the cosmos. So they are regularly removed from the telescope, taken down the mountain to the recoating facility, cleaned and finally recoated with a thin and highly reflective new aluminium layer." [These Are the Biggest Telescopes on Earth]
The mirror-cleaning process takes eight days and includes removing the mirror from its telescope and transferring it to a recoating plant. While it may look like a relatively relaxed process in this video, it's actually a tense operation, ESO officials explained.
The Very Large Telescope is one of several observatories operated in Chile's Atacama Desert by ESO.
Editor's note: Space.com senior producer Steve Spaleta contributed to this report.