KEEN amateur stargazers gathered in York today to take the once-in-a-lifetime opportunity to observe the transit of Venus across the face of the sun.

At 6.19am, the Earth's closest planetary neighbour began to cut a diagonal path across the bottom of the sun.

Appearing as a black disc 30 times smaller than the sun's diameter, it moved from left to right over the course of six hours.

The event, which ended at 12.23pm, does not occur again until June 6, 2012 - but on that occasion will be hidden from British sky-watchers.

They will have to wait until 2247 to see Venus make another journey across the sun.

Excited observers hoped to catch a glimpse of the phenomenon in York's Museum Garden's Observatory. The transit was also beamed in from the internet onto a giant screen in the Tempest Anderson lecture hall.

Costumed character Jeremiah Horrocks was also in the gardens to tell visitors how he used a simple telescope and surface to watch the event in 1639.

Meanwhile, visitors to City of York Council's Copmanthorpe Library got the chance to witness the transit under the guidance of British Astronomical Society member Hazel Collett, from the York Astronomical Society.

Updated: 10:41 Tuesday, June 08, 2004