Tuesday 8th June 2004
Public Observing of the Venus transit on 8th June
The EAAS were at the Seven Towers roundabout, Ballymena, County Antrim for the entire Venus transit which began at 0519GMT through to 1124GMT. In the first 2 hours, we had a surprising number of visitors and many going to work, stopping by and having a look. The first early birds arrived at 6:45am !!!
The SolarScope is now part of the EAAS solar observing equipment and a very valuable asset for transits and solar eclipses.
Resident astrophotographer, Mark Stronge with his 10" Meade LX200. In the far right photo, our youngest member Christopher Gault is setting up his telescope which he used to capture an excellent sunspot image recently.
Many crowds of people came throughout the day to catch a glimpse of the transit. In the far right photo, Aaron Hunter, new member to the EAAS and also the only person to capture any image of the transit.
From the oldest to the youngest, we all took note of this planetary alignment and felt quite privileged to observe it as it happened.
A family from County Kildare joined us for the excitment of the chase.
The weather for 1st and 2nd contact was variable and we managed to see a half disk before the clouds thickened again. During the transit, Venus was visible in many short bursts and there was frantic shouts and exclamations of success in viewing this rare astronomical event before the clouds rolled in again. The public and EAAS members were out in force of which all got to see the transit live and also via a webcast from Norway. The webcast from Ballymena was dissappointing as the short bursts of clear seeing did not give enough time for any photographs to be captured or broadcast. One photo was captured mid transit by Aaron Hunter, one of our new members, and it is pictured below.
Thanks go out to the 5,000 people who visited the website on 8th June (nearly 7000 page views) looking for a live webcast of the Venus transit. I hope you clicked through from our link to the Norwegian webcasts which had 95% success. This sheer number of people on the website in only a few hours is quite astonishing and trumps our previous busiest day from the Lunar Eclipse last November. Thankyou for visiting and I hope you will be back soon.
On Tuesday 8th June, children will join amateur and professional astronomers to witness one of the rarest events seen from the British Isles. The planet Venus will pass between the Earth and the Sun, in a phenomenon called a transit of Venus. All of the “8th June 2004 Venus transit” will be visible from the United Kingdom, along with most of Asia, Africa and all of Europe. Part of the event will be seen from Australasia, eastern North America and most of South America except the southern parts of Chile and Argentina.
The orbital plane of Venus lies at an angle of just under 3 1/2 degrees to the Earth’s orbital plane, known as the ecliptic. Transits, and eclipses, can only happen when the third body lies on, or very close to, that plane. This condition is only realised at two points on Venus’s orbit where it crosses the ecliptic going from below it to above it, called the ascending node, or from above to below it, called the descending node. Transits of Venus happen in pairs eight years apart. The interval between the second of one pair and the first of the next alternates between 122 years and 105 years.
Total transits of Venus, when its crossing can be seen from beginning to end, are extremely rare. The last complete transit of Venus occurred on 23rd May 1283 and lasted from about 2pm until 7.25pm when the Sun was still 16˚ above the horizon. The next Venus Transit entirely visible from the UK will not take place until 11th June 2247 when mid transit will be at noon GMT. The last incomplete transit of Venus, when part of its path across the Sun could be observed, occurred in 1882.
Transits, which should never be observed directly without proper filtration, have only occurred six times since telescopes were first used in the early 17th century. This time, schools and amateur astronomy clubs across the British Isles and Europe will take part in a mass observation that repeats an experiment performed by a little-known English astronomer called Jeremiah Horrocks, who in 1639 was the first person to predict and observe a transit of Venus.
In the 17th century the true distances between the planets and the Sun were not known. They could only be known if the true distance of one planet from the Sun, in kilometres, was known. This could be found by timing the transit of Venus from several places on the Earth and using the parallax effect with trigonometry to find the distance to the Sun. This distance is known as the Astronomical Unit or AU and we will be joining with others across Europe on 8th June to precisely time the ingress and egress of Venus on the disk of the Sun. The astronomical unit is the baseline for stellar parallax determinations, and is thus the first step of the cosmic distance scale. Below are the approximate times of contact for Belfast.
1st Contact 0519hrs GMT
This time, the transit begins at about 6.20am BST on 8th June, shortly after sunrise, when the black disc of Venus appears to kiss the outer edge of the Sun. The entire transit takes about six hours, with mid-transit due at 9.22am and Venus leaving the Sun at about 12.04pm.
Points of Interest