Clouds dim Venus transit over Sun


There was disappointment for hundreds of people who turned up this morning at Skerries harbour in north county Dublin to watch a rare transit of Venus.

The transit, where the planet passes in front of the sun, would have been visible in Ireland for an hour this morning between 4.50am and 5.50am had the skies been clear.

However, rain and cloud cover meant there was no possibility of observing the transit from the east coast.

The Dublin Institute of Advanced Studies and DIT were ready to participate in a global experiment to measure the time that Venus crossed the face of the sun. This is being used to determine the exact distance between the Sun and the Earth, known as the astronomical unit.

Skerries was also chosen for the Venus watch because of its links with a famous experiment in 1769 when British astronomer Charles Mason landed in nearby Balbriggan to observe the transit that year.

In that year Captain James Cook went to Tahiti as part of a worldwide experiment to use the Venus transit to measure distances in the solar system.

Earlier today other people throughout the world had a better experience of seeing this year’s transit. The transit was visible throughout the seven hours Venus was passing in front of the Sun in east Asia and North America.

Astronauts on board the International Space Shuttle were also able to observer the transit unencumbered by clouds.

Scientists used this year’s transit to conduct a series of experiments which will be used in the hunt for exoplanets orbiting around other stars. They tested methods to measure the atmosphere of Venus which it is hoped will be successful in detecting the atmospheres in distant planets.

The disappointment for Irish stargazers will be compounded by the realisation that the next transit will not be for another 105.5 years and even then in 2117, it will not be visible from Ireland.