HET Mirror and Louvers

HET

This interior view of the dome of the Hobby-Eberly Telescope reveals its segmented mirror, the dome opening, and the open louvers that look like blinds which encircle the structure. When open, the louvers allow cool air to flow through the dome, keeping the temperature inside as close as possible to the temperature outside. This helps to maintain the quality of astronomical observations. Credit: Ethan Tweedie Photography