The public will have a once in a lifetime opportunity to see a rare sighting of Venus passing the sun on Tuesday morning.

Eddie McGonagle of the Astronomical Society of Bermuda said it only happens every 122 years. "Nobody living has seen this phenomenon in our lifetime," he said, "It will pass across the sun rather than over it. It will take about five or six hours to pass. It is called transiting.

"In Bermuda we will see it passing beginning at dawn on Tuesday for about one-and-a-half-hours and it will be over at 8 a.m. It will look like a little dot going across the sun."

Mr. McGonagle said people in countries further west will see it for a longer period of time. But he warned viewers to protect their eyes, as it was not advisable to look directly at the sun.

"Do not look at the sun through binoculars or with bare eyes as the damage can be instantaneous," he said. "The damage is in the retina and it can't be felt because there are no pain receptors."

Mr. McGonagle said his telescope had a solar filter, which would provide him with quite a dull image. "But if you don't have a telescope you can make a viewer out of two pieces of card or a piece card tubing from a paper roll," he said.

To make a simple sun projector:

You will need two pieces of stiff white paper and one pin

A sunny day and perhaps a friend to help

With the pin, punch a hole in the centre of one of the pieces of paper

Go outside, hold the paper up and aim the hole at the sun

Now find the image of the sun that comes through the hold

Move your other piece of paper back and forth until the image rests on the paper and is in focus or has a nice crisp edge.

What you are seeing is not just a dot of light coming through the hole, but an actual image of the sun and the dot passing across it is Venus during transit.

@EDITRULE:

If you want more information on how to make a cardboard viewer, contact Mr. McGonagle on 236-3780.