Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2007 August 21

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A Red Dome Under the Big Dipper
Credit & Copyright: M. Colleen Gino

Explanation: Why would the dome of a telescopic observatory appear translucent red? As one of the telescopes of the Etscorn Observatory of New Mexico Tech waited to inspect small portions of the night sky, playful observers decided to make this unusual image. Tricks needed to create this seemingly impossible shot included opening the observatory dome slightly, using a red light to illuminate the inside of the dome, spinning the dome, and using a long exposure. The open slit in the dome then allowed the camera to incrementally image the inside of the observatory, including the telescope. A fortuitous break in the clouds allowed the stars of the Big Dipper asterism to shine through.

Tomorrow's picture: big tarantula

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