Mercury Transit May 2003

A rare event happened on Tuesday 7th May 2003, Mercury, the innermost planet, was in transit, or moved across  the face of the Sun. So-called transits of Mercury only occur on average 13 times a century and a grazing transit like this one is extremely rare. The next one will not occur until 2314.

The transit is now over but what a sight! EAAS webmaster David Mullan met members of The Irish Astronomical Association at their IAA public 'Mercury - Watch' in the grounds of Belfast City Hall and was treated to fantastic views of the of transit, one through a 70 mm refractor with a sun filter, another via projection from an imposing looking 6" refractor. A few timid members of the public also looked in and showed approval with wows! and similar expressions.

In the event, worries about cloud were unfounded and at about 8.30 am the weather was absolutely perfect and great views where afforded of the transit - crisp small disk of mercury stark against the brilliance of the sun. As well, 5 or 6 large well defined sunspots were easily seen showing umbra and penumbra. (Sunspots are made up of two parts: a dark, roughly circular central disk called the umbra, and a lighter outer area called the penumbra.)

For a full and detailed account of the Transit as seen by EAAS Member Billy Graham click here....

For a full and detailed account of the Transit as seen by IAA President Andy McCrea click here....

Below, see shot taken by EAAS member Harry Kernaghan

omc.jpg (17380 bytes)

For more details why not see Armagh Observatory's gen. on the transit at

There's also a NASA site:


  Public Web Stats
Last Updated : Friday, December 3, 2020

All content is Copyright © EAAS, authors and images.The East Antrim Astronomical Society is based inBallyrobert, County Antrim, Northern Ireland.