Diurnal motion
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In astronomy, diurnal motion is the apparent motion of celestial objects around Earth, or more precisely around the two celestial poles, over the course of one day. It is caused by Earth's rotation ar
Star trails captured during a total lunar eclipse
Star trail
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A star trail is a type of photograph that uses long exposure times to capture diurnal circles, the apparent motion of stars in the night sky due to Earth's rotation. A star-trail photograph shows indi
Diurnal motion
…caused by Earth's rotation around its axis, so almost every star appears to follow a circular arc path, called the diurnal circle, often depicted in star trail photography. The time for one complete rotation is 23 hours, 56 minutes, and 4.09 seconds – one sidereal day. The first experimental demonstration of…
All the stars in the night sky appear to circle the celestial pole (the south pole in this photo). Over a period of several hours, this apparent motion leaves star trails.
Star trail photographed from Mount Wellington, Tasmania. Aurora australis visible in the background.
Star trail photography on salt lake in Lut desert in Iran
Star trails photographed from the International Space Station in low Earth orbit at an angle that makes the trails almost vertical instead of circular.