06/04/2012 12:07 pm ET Updated Jun 05, 2012

Venus Transit Denver: Where To Watch The Once-In-A-Lifetime Astronomical Event In Colorado

Get ready for another rare celestial event Colorado skywatchers! Get your pinhole projector and solar viewing glasses ready because a rare sight of the planet Venus slowly moving across the face of the sun will be visible in Colorado (weather permitting) Tuesday afternoon -- and it won't repeat for more than 100 years! A truly a once-in-a-lifetime event.

Dubbed the "transit of Venus", the second planet from the sun will appear as a small black dot gliding across the disk of the sun on Tuesday, June 5 beginning around 4 p.m. Even though Venus is the size of Earth, the sun will appear nearly 100 times larger, according to Dr. Doug Duncan, Director of CU-Boulder's Fiske Planetarium.

The transit of Venus is an extremely rare celestial event that has only occurred 53 times cince 2000 B.C. Although the path of Venus' orbit takes the planet between the sun and the Earth about every year and a half, it doesn't always line up -- Venus often passes above or occasionally below the sun, from the Earth's perspective -- to create this kind of astronomical event. has compiled an interesting transit of Venus gallery as it has been recorded throughout human history.

The whole event takes about 6 1/2 hours and will still be going on after sun sets here in Colorado, meaning we should have about four hours of viewing time during the transit. Here is Tuesday's transit of Venus schedule:

  • 4:05 p.m.: Venus begins transit across the face of the sun
  • 8:27 p.m.: Sunset

This will be the last transit of Venus unti 2117, The Denver Post reports, so don't miss out on this opportunity.

Be sure to pick up a pair of eclipse watching glasses -- REGULAR SUNGLASSES WILL NOT DO! Watch Dr. Doug Duncan, Director of Fiske Planetarium talk about safe viewing of the sun below the slideshow (Note: video is in reference to the solar eclipse from May, but same rules apply to the transit of Venus viewing).

Skywatchers can set up a chair, put on their solar viewing glasses and watch the show just about anywhere there are not obstructions around them on the ground that could block their view of the sun, but there are some hosted events going on around town that should prove to be fun:

  • Beginning at 5:30, Gates Planetarium at the Denver Museum of Nature & Science will be holding a discussion led by scientists Ka Chun Yu and Bob Reynolds and viewing with safe solar telescopes.
  • The Denver Astronomical Society will also be hosting a viewing at Observatory Park and viewers can watch the transit through the 20-inch Alvan Clark-Saegmuller refractor.
  • Fiske Planetarium at Boulder will also be open during the transit and those interested can view Venus through safe telescopes.

But if you want to observe the eclipse away from the crowds, try one of these beautiful spots:



Where To View The Transit Of Venus In Colorado