Richard Harwood

Venus Transit 2004

Viewing the Venus Transit of 2004

On June 8th, 2004 one of the rare transits of Venus across the face of the sun occurred. During a transit, the orbit of Venus places the planet directly between the Earth and the sun, thus it appears to move across the face of the sun. This only occurs rarely because the plane of the orbits of the Earth and Venus are not exactly the same. Normally Venus appears to move either above or below the disc of the sun as it orbits the sun. When conditions are right, a transit occurs. Only five previous transits are known to have been observed. These occurred in 1639, 1761, 1769, 1874 and 1882. The June 8th, 2004 transit makes number 6. The next transit will occur on June 6th, 2012.

The historical importance of a transit was that it helped astronomers determine the distance between the Earth and the sun, and thus allowed for the estimation of the distances to the other planets.

The June 8th transit was only partially visible from the Quad Cities Area. At sunrise, most of the transit had already been completed, only the tail end of it was visible. Viewers in Europe, most of Asia, and a large part of Africa were able to view the transit in its entirety. Viewers in Australia were able to view the beginnings of the transit before sunset. Viewers in the eastern portions of North America and South America were able to see the end of the transit just after sunrise.

The images below were taken from a location south of Coal Valley, Illinois on the edge of some farm fields. They were taken using a Pentax *ist D digital camera in conjunction with an 8 inch Meade Schmidt-Cassegrain telescope. As the first picture below shows, viewing conditions were less than ideal at sunrise. The humidity levels had remained relatively high throughout the night, and at dawn the sky was hazy with a bank of clouds moving eastward. Fortunately, there was a break in the clouds at the horizon which allowed us (Richard Harwood and Doug Davidson) about a 20-minute window of viewing. We were unable to see the very end of the transit, but saw enough to get a few pictures. The "wavy", fuzzy, and distorted appearance of the pictures is due to the fact that the sun is near the horizon - that means we were looking though a lot of atmosphere. The atmosphere is in motion and dynamic - not ideal conditions for astronomical viewing.

Click on the image to view the full size image.

Sunrise on June 8th, 2004
Sunrise on June 8th, 2004. Note the cloud bank heading towards the horizon.

Just after sunrise
Just after sunrise. Venus is the dark spot on the right. The trees on the horizon are visible as silhouettes on the disc of the sun. The fuzzy horizontal lines are power lines.

The sun is clear of the horizon
The sun is clear of the horizon.

he sun continues to rise behind a bank of clouds
The sun continues to rise behind a bank of clouds.