Star Trails at Lake Ninan, Western Australia

Star Trails at Lake Ninan, Western Australia

Star trails are caused by the Earth’s rotation. It makes stars appear to move in arcs and circles around the Earth’s celestial poles (the celestial south pole is seen to the left in this image). The distance of each star to the pole star helps us define that stars are circumpolar or seasonal. Circumpolar stars do not rise or set like the Sun—they would even be continuously visible during the day at any time of the year if not for the Sun’s light. Meanwhile, seasonal stars rise in the east and set in the west, changing with the seasons due to their proximity to the celestial equator. These pathways are an effect of the geometry of Earth’s orbit, and the latitude you observe the sky from will change what stars appear circumpolar.

Photographer Trevor Dobson: "This is a 999 shot star trails image taken at Lake Ninan, 2 hours north east of Perth in Western Australia. Started these at 7pm and finished at 4am."

Image details: Nikon d5500, 11mm, 999 x 30 seconds, ISO 1250, f/3.2

Image Credit: Trevor Dobson
Image Date: Sept. 20, 2025
Release Date: Oct. 2, 2025

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