Eclipsed moon, striking night sky

A total eclipse of the Moon is an impressive spectacle. But it also provides another viewing opportunity: a dark, moonlight-free starry sky. At Cerro Paranal in the Chilean Atacama Desert, one of the most remote places in the world, the distance from sources of light pollution makes the night sky all the more remarkable during a total lunar eclipse.

This panorama photo, taken by ESO Photo Ambassador Yuri Beletsky, shows the view of the starry sky from the site of ESO’s Very Large Telescope (VLT) at Cerro Paranal during the total lunar eclipse of 21 December 2010. The reddish disc of the Moon is seen on the right of the image, while the Milky Way arches across the heavens in all its beauty. Another faint glow of light is also visible, surrounding the brilliant planet Venus in the bottom left corner of the picture. This phenomenon, known as zodiacal light, is produced by sunlight reflecting off dust in the plane of the planets. It is so faint that it’s normally obscured by moonlight or light pollution.

During a total lunar eclipse, the Earth’s shadow blocks direct sunlight from the Moon. The Moon is still visible, red in colour because only light rays at the red end of the spectrum are able to reach the Moon after being redirected through the Earth’s atmosphere (the blue and green light rays are scattered much more strongly).

Interestingly the Moon, which appears above one of VLT’s Unit Telescopes (UT2), was being observed by UT1 that night. UT1 and UT2 are also known as Antu (meaning The Sun in Mapudungun, one of Chile’s native languages) and Kueyen (The Moon), respectively.

Links

• ESO Photo Ambassadors webpage

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