Photographing The Precession of Earth
This is a camera mounted on two clock drives. The axis of one clock drive points at Polaris, and rotates opposite to the spin of Earth. This freezes the motion of stars around today’s North Star. The axis of the second clock drive points at Vega, and transfers the spin of our planet there. This contraption allowed Claro to compare the North Stars, Polaris vs. Vega, in the form of star trails
The North Star is Polaris, but it wasn’t always Polaris. Thousands of years ago, the spin axis of Earth pointed toward another star–brilliant Vega. This is because Earth, akin to a spinning top, slowly wobbles or “precesses”. Astrophotographer Miguel Claro has long wondered what the sky would look like if Vega were still the North Star.
“After a long time of burning my mind with new ideas,” says Claro. “I figured out how I could do it, developing what I think is, a totally new astrophotographic technique.” Here it is:
“All the images were taken from the Mourão Castle, in the Dark Sky Alqueva Reserve, the First Starlight Tourism Destination in the world, in Alentejo, Portugal,” says Claro.
Claro’s multi-drive system causes the landscape to move during the exposure. “I made a mask merging the landscape with the first frame to have a more pleasant result,” he explains. More information about his technique may be found here.
Earth wobbles with a period of about 26,000 years. In only 14,000 years, Vega will become the North Star again. Thank you, Miguel Claro, for the preview.