Grand Canyon Star Trails

Astronomy Picture of the Day · 2013-03-03 · NASA (public domain)

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Grand Canyon Star Trails — APOD for 2013-03-03

One of the natural wonders of planet Earth, the Grand Canyon in the American southwest stretches across this early evening skyscape . The digitally stacked sequence reveals the canyon's layers of sedimentary rock in bright moonlight. Exposed sedimentary rock layers range in age from about 200 million to 2 billion years old, a window to history on a geological timescale. A recent study has found evidence that the canyon itself may have been carved by erosion as much as 70 million years ago. With the camera fixed to a tripod while Earth rotates , each star above carves a graceful arc through the night sky. The concentric arcs are centered on the north celestial pole, the extension of Earth's rotation axis into space, presently near the bright star Polaris .

Astronomy Picture of the Day for 2013-03-03 — image & explanation courtesy of NASA (public domain), mirrored at Tukuk-OS for reading and search convenience.

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