Does it feel like we've been looking up in the sky at various planetary rarities a lot lately? Well, add another cool event to the list. Transit of Venus, which occurs when Venus passes directly between Earth and the sun and appears as a small dot gliding slowly across the face of the sun, will be viewable today from 3 p.m. (PST) this afternoon until sunset. The event, which occurs in pairs - the first half of the current transit took place in 2004, won't be happening again for another 100 years. The last transits occurred in 1874 and 1882.

California Academy of Sciences is having a Transit of Venus celebration today from 11 a.m. to 4 p.m., featuring astronomy games, puzzles and more, and patrons can view the event on the Academy's living roof through solar telescopes from 3 to 5 p.m. The transit will peak at 6:25 p.m. (PST). They also have tips on viewing the alignment.

The Exploratorium will be live streaming the Transit of Venus from Hawaii’s Mauna Loa Observatory, which is located on the north slope of the Mauna Loa volcano at an elevation of more that 11,000 feet, starting at 3 p.m..

Be sure to check out transitofvenus.org's list of Safe Viewing Techniques. Keep those eyes safe, folks!

As always, tag your beautiful planetary event photos "sfist" on Flickr!