As the World Turns: Night Sky Photographer Snaps Earth's Precession

The Earth's precession is captured in stunning detail in this image by a veteran astrophotographer.

In an email to Space.com, night sky photographer Miguel Claro said he developed a new photo technique  showing a Vega "polar" star trail. The image was taken from inside the Mourão Castle, in the Dark Sky Alqueva Reserve, the First Starlight Tourism Destination in the world, in Alentejo, Portugal.

Earth's axis changes over time due to a phenomenon called "precession," which pulls the direction of the axis in a circle that takes 26,000 years to trace out in the sky. What this means is the direction of north changes in the sky over time. A consequence of the precession is a changing pole star. Typically, Polaris is used to mark a position but Claro says he was fascinated with the possibility of using a different star. But because of Earth's precession, the star Vega will likely serve as a new North Star in the year 14,000, even though it never comes closer than 5 degrees to the celestial pole, Claro wrote. [The Brightest Stars in the Night Sky]

 But what would that look like to future astrophotographers?

In a post on his website, Claro explains how he used two star-tracker mountings to help create the views of both Polaris and Vega serving as the North Star in the image above. He also posted a video of the skywatching feat on Vimeo.

Claro used a Canon EOS 6D - Canon EF 8-15 f/ 4L Fisheye USM at 8mm (All Sky) at exposure 30 seconds and ISO 2500 to create the images.

To see more amazing night sky photos submitted by Space.com readers, visit our astrophotography archive.

Editor's note: If you have an amazing night sky photo you'd like to share for a possible story or image gallery, please contact managing editor Tariq Malik at spacephotos@space.com.

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