KALISPELL – A rare celestial event observed just six times in modern history will occur on June 5 as the planet Venus traverses the face of the sun. In the Flathead Valley, skywatchers can join the Big Sky Astronomy Club to discuss the significance of the transit and observe the stunning sight through solar-filtered telescopes.
Known as “The Transit of Venus,” the planet will be visible as it passes between Earth and the sun for the second and final time this century, appearing in tiny silhouette from earth’s perspective as a slow-moving black dot trekking across the face of the sun.
The Big Sky Astronomy Club will have special solar-filtered telescopes at the ready, and is inviting members of the public to view the planetary transit, which will not occur again until the year 2117.
At 2:30 p.m. at the Flathead Valley Community College, club president Mark Paulson will give a presentation on the significance of this celestial event and what to expect. Afterward, anyone can safely view the event through telescopes that have special solar filters in place.
“These are such rare events because they usually occur in pairs every 105 years, so for most people it’s a once in a lifetime opportunity,” Paulson said.
The upcoming transit had a partner event in 2004, and previous events occurred in 1874 and 1882.
The June 5-6 transit follows closely on the heels of the “Ring of Fire” solar eclipse that occurred May 20, when the moon passed between the Earth and the Sun. Paulson was in Bryce Canyon, Utah, to watch the remarkable eclipse, during which the moon covered most of the sun’s disk but left a ring of light blazing around its circumference.
The Venus transit promises something much more rare – a precise alignment of the sun, the Earth, and another planet, Paulson said.
Venus will be seen as a small dark circle against the bright backdrop of the Sun. The transit begins at 4:05 p.m. and will be in progress as the sun sets at 9:35 p.m. Remember to never look directly at the sun, Paulson warned, especially with unfiltered binoculars or telescopes. Even a brief glimpse can cause permanent blindness.
Historically, astronomers took advantage of the unusual events to measure the size of the solar system, said Big Sky Astronomy Club member Eric Hilton.
Researchers mounted large expeditions all over the world in order to make precise observations of the time when the transit started. Although modern astronomers know the distances between celestial objects, a group called Astronomers Without Borders is calling on anyone with a smart phone to help them repeat the historic measurements. The free apps are available for both iPhone and Android, and will enable observers from all over the world to participate.
“One of the biggest problems in astronomy is trying to figure out how far away things are from each other, because the distances are huge and it’s not like you can just hold a tape measure up to the sky,” Hilton said. “So for a long time we had a very poor idea of distances between different points, and these transits helped astronomers compute the distance.”
The best method for viewing the transit is through telescopes equipped with solar filters, since the telescope will magnify the image and the filter will prevent eye damage.
Other options for safely viewing the transit include pinhole projectors, specially made filters, or watching on television or online.
If you miss this transit, you’ll have to wait until the next one comes around in 2117.
In the meantime, the Big Sky Astronomy Club will offer other opportunities for viewing the night sky through a telescope. They are hosting events at Lone Pine State Park on July 14th, and Logan Pass in Glacier National Park on July 20th and August 17th.
Questions about the transit or any of the BSAC activities can be directed to club president Mark Paulson by emailing him at firstname.lastname@example.org.
Missoulian Flathead Valley Bureau reporter Tristan Scott can be reached at (406) 730-1067 or at email@example.com