Mercury Transit

May 14, 2003


Provided by: Anthony Ayiomamitis
Summary authors & editors: Anthony Ayiomamitis; Jim Foster

The above photo was taken from Athens, Greece on May 7, 2003 during the transit of Mercury across the face of the Sun. Mercury is the black dot near the top of the Sun, below the yellow arrow. The miniature silhouette of the planet zipped across the Sun's face for the first time since 1999. In the U.S., only residents in Alaska, just before sunset, and the extreme northeastern states, shortly after sunrise, were able to glimpse the transit. This event is relatively rare as it occurs, on average, about thirteen times each century. The transiting Mercury had an apparent diameter of only 12.0 arc-seconds or approximately 1/160th that of the Sun.

Aside from being the closest planet to the Sun, Mercury is the second smallest planet of our solar system -- only Pluto is smaller. It rotates completely around the Sun once every 88 days, and it has such a slow rotation about its axis that a day on Mercury is greater in length than its year (time required to orbit the Sun).

This photo was obtained using a focal projection with a Nikon Coolpix 995 camera and a TeleVue Pronto, working at f/6.5 and piggy-backed onto a Celestron 14" SCT.

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