The AAT dome from the Director's Cottage, moonless sky
The 1200 m summit of Siding Spring mountain is 350 km inland from Sydney, Australia's largest city, and quite isolated from other sources of light at night. Such darkness is highly valued in astronomy so artificial lights are strongly discouraged at the Observatory. However, people have to move around and are obliged to use hand torches (flashlights in the USA). These appear as wavy lines as they are carried by astronomers walking to and from the AAT dome. Also, any movement of a vehicle by night is made on parking lights so that no stray light interferes with observations. That light-spill is seen on the left of the picture.
This night-time activity has been captured on a long-exposure photograph, which was made mainly to record the trails of stars rising in the south east of the AAT dome, in the foreground. A moonlit view of this scene is here
, and more information on star trail photography is here
Credit: David Malin
© Australian Astronomical Observatory