Skywatchers will be hoping for clear skies on Wednesday to help them see the Transit of Mercy.

At approximately 3.12 on Wednesday afternoon Mercury will move in front of the Sun and for the next five hours Mercury's silhouette will show against the Sun's bright disc as it moves diagonally from lower left to right. The Bermuda Sun will however set at 5.15 before the transit is complete.

The Astronomical Society of Bermuda has warned that members of the public should not attempt to view the transit with the naked eye. President Eddie McGonagle said optical aids with proper solar filters should be used.

He said the screw in the eyepiece sun filter supplied on some telescopes in not sufficient to ensure safety.

"The safest method is to project the Sun's image through a telescope or binoculars on to a white background as in a simulated photograph. This method allows more than one person to observe. A shadow card fitted behind the eyepiece tube enhances the contrast."

He said extra caution should be taken to cover the telescopes finder or the second barrel of the binoculars.