Compiled by Kathy Krause from various Days Past articles written by Nancy Kirkpatrick Wright

The following article is a compilaiton that has been revised and updated by Kathy Krause.  All articles were originally written by Nancy Kirkpatrick Wright.

Eight years ago, on Tuesday morning, June 8, 2004, the bright planet Venus moved in front of our sun - a transit of Venus - and millions watched through strong filters as a small black dot moved across the sun.

Scientists and astronomers were excited since no one then alive had seen a transit of Venus. There were no transits of Venus in the 20th century; the last ones occurred in December of 1874 and December of 1882.

On Tuesday, June 5, there will be another transit of Venus, the very last this century. This is a rare event, happening in pairs, eight years apart separated by long alternate gaps of 105.5 and 121.5 years. The last pair was 1874/1882, the current pair 2004/2012, and the next pair will be 2117/2125. If you miss seeing this current one, you will never have the opportunity again!

So, just what is a transit of Venus? It occurs when the path of our closest neighbor planet, Venus, moves in its orbit between the Earth and the sun. Because the orbit of Venus is slightly tilted, the planet usually passes above or below the solar disk when it overtakes the Earth's orbit (every 16 years). Thus, very rarely are we treated to see Venus projected onto the sun as a small, black silhouette - the transit of Venus. The planet moves slowly, taking about five to six hours to cross from one edge of the sun to another.

Historically speaking, in December 1874, Prescott was 10 years old and the weekly Arizona Miner published this one-liner: "Teheran, Asia, Dec. 9 - The observations of the Transit of Venus here were very successful." No one took much note of it. Local headlines that week reflected disagreements between cattlemen and farmers, "Fence or no Fence," as well as the usual political blustering: "malicious liar," "unmitigated falsehood" and "connivance in the use of government property." In the Territorial Legislature, a bill had been introduced to build a penitentiary. Furthermore, two women were shot at the Saturday night fandango on Whiskey Row.

Eight years later, upon the transit of Venus' twin occurrence, December 1882, the Miner failed to record it at all. Frederick Tritle was the newly appointed Territorial governor and he 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." He needed a more peaceful territory in order to pursue statehood. Eighteen-year-old Prescott boasted about 5,000 residents, five churches, two schools and 18 saloons. News revolved around stage robberies and, of course, the usual fandangos on Whiskey Row. 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.

Even the great American "March King," John Philip Sousa, apparently watched the 1882 transit, for he soon wrote a musical march, "The Transit of Venus," and a novel of the same title. Sousa's music was destroyed in a flood, but an old copy has been found in the Library of Congress and the march has been described as "a little 3-minute gem." Chances are you will hear this march played on radio or TV sometime between now and June 5.

Before the invention of the telescope in the early 1600s, a few astronomers thought they had seen a transit of Venus, but they were actually seeing very large sunspots. As far as we know, only six transits have been witnessed by humans: 1639, 1761, 1769, 1874, 1882 and 2004.

Astronomer Edmond Halley (of comet fame), like scientists for hundreds of years before him, was, in 1716, seeking a way to measure the distance from Earth to the sun using the Gregorian telescope. He proposed that if the transit of Venus was observed from many widely separated stations, the tracks across the sun and the time they took could be recorded and compared and the distance to the sun could be calculated.

Even though Halley died in 1742, the 1761 transit was watched at some 70 stations around the world, (the largest scientific attempt up to that time). The results were disappointing. Bad weather, navigational errors and difficulty timing Venus's image against the sun all contributed to the failure.

For the transit in 1769, scientists planned more carefully and managed to send out many observing parties, including the intrepid British seaman, Capt. James Cook. Young Capt. Cook witnessed the transit of Venus in 1769 from near Tahiti during his first journey to the South Seas. In fact, the main purpose of this voyage was to observe and take measurements of the transit of Venus.

He took the transit very seriously. His ship, the Endeavour, with a couple of scientists and a lusty crew, set out for the South Pacific and managed to view the whole thing. 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). The rough calculations gathered by Cook and others that day, according to Halley's instructions, gave the best Earth-sun distance at the time.

Today there are better ways to measure astronomical distances and we can entertain ourselves for hours looking up transits of Venus on the Web. Scientific books are being published on the subject as well as novels, magazine stories and newspaper articles. It's historic. It's a rare event. It will be visible over most of the northern part of the Earth to varying degrees. It will appear as a small black dot with a bright ring around it.

Remember the date for us here in Prescott: June 5, (transit in Europe will occur at sunrise on June 6). Using a #14 welder's filter or a telescope with a solar filter (do not attempt to view it without proper eye protection - sunglasses are not adequate), the transit will begin at 3:06 p.m. (MST) and end at 9:47 p.m. (two hours after sunset ... we will miss the last two hours of the transit).

For instructions on ways to view it safely from your home, more information about the transit of Venus and locations and specific times, go to www.transitofvenus.nl.

For public viewing of the Transit of Venus, solar telescopes will be available at the Prescott Public Library and at the Quad at Yavapai College on June 5 from 3:30 p.m. until sunset.

Astronomers without Borders/Courtesyimage
Above are Venus transit times and appearances in the Prescott area. Solar telescopes will be available at the Prescott Public Library and at the Quad at Yavapai College from 3:30 p.m. until sunset June 5.