The Vatican Observatory at the Papal palace at Castelgandolfo is the site of a large congregation of astronomers this week who are in town to observe the transit of Venus.

An astronomical transit takes place when an object such as a planet passes directly in between to others. In this case Venus passes between Earth and the sun. Venus transits two times, eight years apart, every 130 years.

This is the sixth transit ever to occur since the invention of the telescope, the last one being in 1882. The next will take place in 2012.

Half of the 90 astronomers present observed today’s transit which occurred between 7.20am and 1.30pm. They are organized by the American astronomy magazine, Sky and Telescope.

As proper equipment is necessary to observe the transit and the Sun safely, in preparation for today's event, the Specola received a gift of a telescope especially equipped for solar observation from the Coronado Technology Group, presented by the group's president, David Lund, on May 31 to Fr. George Coyne, S.J. director of the observatory.

The transit of Venus can be seen as a black dot against the sun by anybody who has a telescope with the necessary safety equipment.