By Nancy Kirkpatrick Wright
Mark your calendar for June 8, 2004, just four years from now. That's when our sister planet, Venus, will dance across the face of the sun for all the world to see.
Last June we talked about Sharlot Hall's trip to Congress, Arizona to see an occultation of Venus, a rare event. Even rarer will be the coming transit when Venus slowly moves across the face of the sun. Transits come along every 122 years, in pairs, eight years apart. The last pair of transits were in December 1874, and December 1882. Sharlot Hall was a four-year old child, living on the banks of Prosser Creek in Kansas in 1874. By December 1882, her family had traveled the Santa Fe trail and settled along Lynx Creek in Arizona Territory.
In 1882, Arizona politicians were arguing about where to locate/relocate the Territorial Capitol, and Governor Tritle was, "determined to enforce the law" so that "ruffianism was coming to a terminus and that a few months more would see the most remote corners of Arizona as free from violence as her sister states and territories." (Prescott Weekly Courier, 4-21-1882). How about that! Word of a phenomenal celestial event had no doubt failed to reach remote mining camps of the West, but scientists around the world were watching closely.
For many years astronomers had looked forward to this opportunity to view the disk of our twin planet silhouetted against the bright light of the sun. They would take measurements to further determine the size of the solar system and gather more information about the atmosphere Venus.
Young Captain Cook witnessed a transit of Venus in 1769, from near Tahiti during his first journey to the South Seas, in fact the main purpose of his first voyage was to observe and take measurements of the transit of Venus. Two hundred years later another poet, a New Zealand balladeer wrote:
Young James Cook was a cabin boy,
He was brave, he was good, he was clever,
He rose to be captain of the king's navy
And commanded the good ship "Endeavour."
He said to his wife, "You're the joy of my life
Though oceans roll between us,
But I must be off to the isles of the south
To observe the transit of Venus."
Who says science is all mathematics and experiments? The heart of the poet finds us all. Captain Cook, of course, took the transit very seriously. Worried about the weather, the officers of the Endeavor hardly slept the night before, but with the help of a "magnifying telescope," they observed the event "with great advantage." It took the planet over six hours to complete the transit-long enough for the ship's crew to get into mischief while the officers were completely absorbed with science (but that's another story.) Cook reported that they saw a "dusky cloud round the body of the planet, which much disturbed the times of the contact." We know, now, that Venus has an atmosphere-a much denser atmosphere than Earth's, and not so transparent-which causes a bright ring of light to surround the black disk of the planet during transit.
When you look in 2004, with a #14 welders filter, you will barely see a small black dot with a bright ring around it. Better to view it through a telescope with a solar filter. Best, though, will be to contact your local astronomy club which will be viewing it safely. In any case never look at the sun without a proper filter as it can severely and permanently damage your vision.
With the invention of radar, much has been learned about the surface conditions of Venus. A series of Soviet landings has sent back photographs of its surface. And, in 1990, the U.S. space probe, Magellan, brought us details of Venus's crust.
Even though a transit of Mercury or Venus no longer has the scientific attraction it did a hundred years ago, it still holds a special fascination for many of us. In just four years we, too, may observe a transit of Venus. If you miss that 2004 event, never fear. The companion transit comes along in 2012. But after that it's a long dry spell until the next one in 2144.
Nancy Kirkpatrick Wright, retired librarian from Yavapai College, is active in Prescott Art Docents and Sharlot Hall Museum. She enjoys investigating the historic confluences of the arts and sciences. She found useful information on occultations and transits along with the Captain Cook poem, in Guy Ottewell's Astronomical Almanacs.
Sharlot Hall Museum Photograph Call Number: (transit drawing). Reuse only by permission.
Mark your millennial calendars now for June 2004 and June 2012. Venus will make a rare transit across our Sun. Using proper filters observers will see a small dot with a bright ring of light - a romantic vision - that happens only once every 122 years.