June 2, 2004 – The last time earthlings watched the planet Venus transit across the sun, some of the world's top scientists did their observing from the Virgin Islands. That was back in 1882. This time the Caribbean is not a hot spot for top-notch watches, but people in the islands should be able to see something for about an hour after dawn next Tuesday.
The excitement of the event comes more from its rarity than its visuals. When the moon passes between Earth and the sun, it eclipses the sun, darkening the day and sending the superstitious scrambling for cover. But Venus — because it is so much farther away — just looks like a small dot as it moves across the sun.
In fact, as far as we know, the transit wasn't noticed at all until the 17th century. That's when Johannes Kepler, the astronomer who discovered that planets orbit in elliptical paths rather than circles, correctly predicted a transit for 1631.
A 20-year-old British astronomer named Jeremiah Horrocks figured out that there would be another one eight years later, and in 1639 he and a colleague became the first people to view the phenomenon through a telescope — which, incidentally, had been invented only 10 years before Horrocks was born.
The whole thing caused quite a stir in the scientific community. Cosmologists saw an opportunity to measure the distance between Earth and the sun if they could compile observations from colleagues viewing the phenomenon from different parts of the globe. But they had to wait until 1761 to try. Transits occur in an irregular, regular pattern: 121.5 years apart, then eight years apart, then another 104.5 years, then eight years, then the cycle repeats.
The next chance to catch the show after Tuesday is June 6, 2012. None of us are likely to be around for the one after that.
Today interest in the transit is both scientific and historical. The Smithsonian Institution Libraries in Washington, D.C., opened a year-long special exhibit in March that is dedicated to the event and its role in the development of cosmology — the study of the universe.
A Virgin Islands-based philanthropic organization, the Peter Gruber Foundation, is a major sponsor of the "Chasing Venus" exhibit and is using it as a backdrop for this year's ceremony to award its annual Cosmology Prize. The award will be presented at the Smithsonian on Friday to Professors Alan Guth of the Massachusetts Institute of Technology and Andrei Linde of Stanford University, who are two leading proponents of the theory of cosmic inflation.
Through publications and artifacts, the "Chasing Venus" exhibit chronicles many of the myriad and sometimes dangerous expeditions mounted in the past two centuries by astronomers seeking good vantage points for observations. While they failed to establish the precise distance between Earth and the sun (92,955,859 miles according to modern calculations), they stirred considerable interest in cosmology. The also gave vent to nationalistic pride while, sometimes at least, promoting scientific cooperation across national boundaries.
In the 18th and 19th centuries, European and other international teams traveled to Siberia, Lapland, Tahiti, Manila, India, the Canadian Arctic and other "exotic" locales, laden with the latest in scientific instruments.
For the December 1882 transit, two countries sent observers to the West Indies: A Brazilian group traveled to St. Thomas and a Danish team came to St. Croix, where it set up shop on Bulowsminde's Hill.
According to St. Thomas historian Isidor Paiewonsky, who devoted several of his "History Corner" newspaper columns in 1982 to the 100th anniversary of those expeditions, the boys from Brazil were considered among the best astronomers of the day. They also had some of the most modern equipment. They hauled it up some 800 feet above the Charlotte Amalie harbor and set up a temporary observatory in what today is Estate Mafolie.
The area was known for a while after that as Venus Hill. The Brazilians stayed on for weeks and they became the darlings of the island social circuit, inspiring boat trips, picnics, parties and masquerade balls.
The Brazilians apparently were equally impressed by their stay and/or by their celestial sightings. As a memorial to the occasion, they built a 13-foot-high concrete obelisk on the site with an inscription commemorating the Passagen de Venus, Dezembro 6 de 1882.
The marker is still there.
St. Thomas Realtor John Foster remembers seeing it for the first time shortly after he came to the island in 1961. "It was in the bush, just a pile of old bricks around it," he recalls.
The property had been a farm for a century or so and also boasted the ruins of a greathouse. In the early '60s, Estate Mafolie was divided up into the first residential subdivision on St. Thomas, and in the process another real estate pioneer, the late Arthur Witty, acquired the land with the obelisk. He renovated the monument and designed his own house to showcase it. The home and structure are still in private hands.
The Venus Hill site is not an ideal spot for viewing the transit this time around. Hills facing to the northeast should provide the best vantage points for next week's event — if you can't get to Asia or Europe in time.
Venus will be nearing the end of its six-hour journey by the time the sun becomes visible in the morning sky over the Caribbean. It is expected to slide past the sun's outer edge completely by 7:26 a.m. Atlantic Standard Time. As precautions against damage to their eyes, viewers are advised to use only telescopes with solar filters and not to look directly at the sun.
For more information, visit the Smithsonian Web site or the Transit of Venus "Frequently Asked Questions" page.
Editor's note: Bernetia Akin is the administrator of the Peter Gruber Foundation.
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