Mercury Elongation

June 17, 2007

Mercury2006feb07 copy

Provided and copyright by: Alan Tough, SIGMA - Moray's Astronomy Club
Summary authors & editors: Alan Tough

The apparent angle subtended by the Sun and a planet, as seen from Earth, is known as elongation. On February 7, 2007, Mercury reached its greatest eastern elongation when it was 18 degrees east of the Sun. It can be seen just above the tree-line at lower right and was shining at magnitude -0.5 when the picture was taken. The much brighter object shown is Venus at magnitude -3.9; its angular separation from Mercury was just over 6 degrees. This image was taken from Elgin, Scotland at 18:18 UT.

Because Mercury orbits so close to the Sun, it's usually quite difficult to observe. Mercury is most often seen just after sunset and rarely after twilight ends.

Photo details: taken with a tripod-mounted Canon EOS 300D camera and a 75-300mm lens, exposure was 5 seconds at f/5 and ISO-200.

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