Astronomy buffs eye Tuesday's transit of Venus with anticipation

Astronomer David Dundee has an out-of-this world offer for anyone who ventures to Cartersville's Tellus Science Museum next Tuesday evening to witness the ultra-rare phenomenon called the transit of Venus.

"We are promising that everyone who comes to watch, if they save their receipts, can get in free to the museum for the next Venus transit," he said with tongue firmly planted in cheek, knowing that there will not be another sighting of the planet's passage between the Earth and sun until 2117. "You know, we know no bounds of generosity."

Actually, astronomy aficionados know no bounds of enthusiasm when it comes to the transit of Venus. Most mortals think of the appearance of Halley's Comet as the rarest of celestial events, visible from Earth every 76 years, give or take. But that is rather commonplace in comparison to the quirky transit of Venus, which won't be spotted from this mortal coil for another 105 years after Tuesday.

People who "collect" astronomical phenomena the way bird watchers check rare winged creatures of their lifetime lists consider the Venus transit, in which the planet appears like a black coin passing right to left across the face of the sun, a holy grail of sorts. That's why they are helping organize viewings across the metro area, from Grant Park to Grayson.

Stone Mountain Park is expecting the largest crowd, easily in the hundreds, who will hike up the mountainside or take the Summit Skyride to the top of "the Rock" before or during sunset. There, members of the Atlanta Astronomy Club will have some 20 solar-filtered telescopes set up for the public to gaze into and 50 pairs of eclipse glasses to lend. (Remember, kids, it's extremely dangerous to stare at the sun without protective filters.)

Atop the outcropping, 1,683 feet above sea level, they will be able to experience a viewing unobstructed by trees or buildings. That means a longer possible viewing -- for about 2 hours and 45 minutes, starting around 6 p.m. -- than anywhere else for miles around, if the skies are not covered by clouds.

"It's going to be great," said Daniel Herron, the club's board chairman and observing chairman. "If the weather is clear, you're raised up higher than anything in the area so you're going to get that extra time. ... We may see 30 or 40 more minutes of the transit because we're a little higher than the horizon.

"I'm really excited," he added, "just extremely excited."

Heck, Spider-Man's senses would no doubt tingle at the chance.

That's because the cycle for transits of Venus, in addition to being rare, are "weird," according to Sky and Telescope magazine, "make that really weird."

Due to multiple factors, alignments of the Earth, Venus and the sun occur in an odd 243-year cycle -- at intervals of 8, 105.5, 8 and 121.5 years. Only seven transits of Venus have occurred since the invention of the telescope, according to NASA: in 1631, 1639, 1761, 1769, 1874, 1882 and 2004.

But even when the bodies align in rare perfection, the weather still must cooperate. The last transit, in 2004, was fully obscured by cloud cover in Atlanta. That was a downer for sky watchers, given how unusual the transits are: The one before 2004 took place way back in 1882, and, after Tuesday's event, the next one won't occur for another 105 years.

Herron, an IT project manager for Siemens, happened to be visiting relatives in Ohio during the 2004 transit, which was already in progress when the sun rose over clear skies. Even though he had three alarm clocks set, he said he barely slept a wink the night before, fearing he'd miss the twice-in-his-lifetime opportunity.

As he was setting up his equipment in the dark, he noticed school children gathering nearby at a bus stop.

"I was wanting to say, ‘Oh my god, don't go to school today,'" Herron recalled with a chuckle. "‘Come over here and look at the Venus transit!"

Tellus astronomer Dundee can understand Herron's urge to promote truancy that day.

Though he acknowledges that Venus transits don’t tend to have as much mass appeal as total solar eclipses or comet sightings, he believes they are something special.

"Some people look at pictures of it and say, ‘Well, it’s a black dot in front of the sun. So what?'" Dundee said. "I just think it's exciting because it's so rare and it’s such a neat thing to see the mechanics of the solar system happening right in front of you."

Transit of Venus viewing opportunities

Stone Mountain Park: Viewings through telescopes provided by Atlanta Astronomy Club members 5-8 p.m. Tuesday atop the mountain. Public can walk up the 1.3-mile trail or ride the Summit Skyride (included in an all-attractions Adventure Pass or available for a $9 round-trip ticket). Standard $10 vehicle entrance fee applies. U.S. 78 E., Exit 8, Stone Mountain. 770-498-5690, www.stonemountain

Tellus Science Museum: 100 Tellus Drive, Cartersville. Telescopes will be set up for public viewing Tuesday evening and a picture from the observatory will be shown on a large screen in the museum's 200-seat auditorium, with commentary by astronomer David Dundee and other staff. After sunset, around 8:40 p.m., images will be provided from a western observatory where the transit will still be unfolding. The museum will close at 9 p.m., the observatory at 10.

A Tellus Planetarium show "When Venus Transits the Sun" continues daily (12:15, 1 and 3:30 p.m.) through June 8. Tickets, $3, with museum admission ($12; ages 65 and up, $10; ages 3-17 and students with ID, $8; free for active military with ID). 100 Tellus Drive, Cartersville. 770-606-5700,

Fernbank Science Center: Atlanta Astronomy Club members offer telescope viewings 4-9 p.m. Tuesday. 156 Heaton Park Drive N.E., Atlanta.

Grant Park: The Grant Park Conservancy and Grant Park Recreation Center in Grant Park offer solar glasses viewings, 6-7:30 p.m. Tuesday near the ball fields. RSVP to 404-521-0938,

Covington: The Charlie Elliott Chapter of the Atlanta Astronomy Club sets up telescopes, 5-8 p.m. Tuesday at Martin's Crossing Shopping Center, 9176 U.S. 278.

Loganville/Grayson: The Charlie Elliott Chapter of the Atlanta Astronomy Club offers telescope viewings at Bay Creek Park (near the soccer field), 175 Ozora Road, Loganville. 5:30-7 p.m.

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