Last Chance: "Transit of Venus" Today, Next One in 2117

Skygazers who watched the should get their safety goggles ready for a celestial event that won't occur again for 105 years.

On Tuesday, the second planet in our solar system will crawl across the surface of the Sun making an epic journey called the Transit of Venus.

If you miss this event, you'll never get a chance to see it. The next Venus Transit won't occur until December 11, 2117.

So says NASA, which has calculated the next 2,000 years worth of transits for those who want to update their day planner.

Sky & Telescope Magazine says the Venus Transit will be visible on the West Coast from 3:06 to 6:26 pm on Tuesday, June 5th.

The Venus Transit is an odd duck, even by astronomical standards.

As NASA explains, the event follows a pattern: two transits occur within eight years of one another. Then there's a long break. This has to do with factors such as the length of a year on Venus (224.701 days) and Earth (365.256 days).

The most recent Venus Transit occurred on June 8, 2004. French composer/conductor Paul Mauriat made a time-lapse video of that event and posted it on YouTube (attached to this story).

How to view it safely

If you do want to view the transit, here are eye-protection tips from Christine Douglass of the American Academy of Ophthalmology:

As with the recent solar eclipse, it's crucial that you choose a safe way to view the transit. Looking directly at it would damage your eye's retina, the light-sensitive area at the back of the eye that provides central vision. 

Safe options include:

• Watch the transit at a planetarium or program by a university astronomy department. Because Venus will look quite tiny against the sun's vast surface, it will be best to watch this amazing event via professional projection on a large screen.
• Visit NASA's website for a live-streaming broadcast and enjoy a live chat with scientists, if you like.
• Make a simple "pinhole camera" using two sheets of paper: make a pinhole in the center of one sheet; then stand with your back to the sun, holding that sheet so that the sun shines through the pinhole onto the second piece of paper. You'll see an image of the transit of Venus projected on the second sheet.

The following devices will not protect your eyes: sunglasses, binoculars with filters, neutral density filters, or exposed photographic or radiographic film.