This afternoon, weather permitting, Utah residents will witness an event not to be seen twice in the same lifetime.
Though slightly less spectacular then the solar eclipse viewed in May, Venus will be passing across the Sun in what is called a planetary transit.
Jeannette Lawler, the Royden G. Derrick Planetarium Director at BYU was not impressed when she found out about today’s forecast.
“We have a 36 inch telescope on campus,” said Lawler. “I’m planning on posting pictures to the (department) website if the weather is decent. If it’s looking like there’s rain moving our way, you cannot risk damaging a million dollar instrument just to get a few pictures.”
The next transit from Venus will occur in 2117 but the next one visible to Utah residents will not be until 2125.
“It’s only twice every 120 years that there is a transit of Venus,” Lawler said.
In a news release, NASA/JPL Solar System Abassador to Utah, Patrick Wiggins said, “Eclipses of the Sun can happen every year and are comparatively common compared to transits of Venus which have been seen by humans only seven times since the invention of the telescope in the early 1600s.”
For students interested in seeing the transit, NASA’s website will be updating pictures from an orbiting satellite, where clouds cannot obstruct the view.
No matter where you are in Utah, and if weather permits, Venus will first start to move in front of the Sun at about 4:06 p.m. MDT. It will spend the afternoon and evening moving very slowly across the Sun.
Staying true to habits we learned during the solar eclipse, proper eye protection must be used to safely view the transit. Regular sunglasses will not work. If you still possess the viewing glasses from May’s eclipse, these can be used along with the welding masks seen from very inventive Utahns,
For additional viewing glasses, the Natural History Museum of Utah and the Clark Planetarium will be selling inexpensive eye wear.
The most recent planetary transit visible from Utah was the transit of Mercury in 2006 with a subsequent visit from the same planet in 2016 and 2019. The Mercury transit will happen 14 times this century, whereas the much rarer event of a Venus transit will happen only twice.
Its not every day that Venus crosses a visible path. Actually if you are in Utah, the event happens about once every 100 years. For fun family events, the Salt Lake Astronomical Society will hold an event, partnering with the Department of Physics and Astronomy at the University of Utah.