The 2004 Venus transit. The transits come in pairs. 2012's transit mirrors 2004's transit. Image Source: The Cosmos News.
Today, Venus crosses in front of the sun from Earth's vantage point. The transit of Venus (beginning at 22:09 UTC on the 5th of June and ending at 04:49 UTC on the 6th of June) is similar to an eclipse of the sun by the moon, except that Venus, being further away, appears to be much smaller. This is one of the rarest of predictable events in the heavens. The Cosmos News:
Space.com: "During a 243 year period only 4 sightings of the transit may be observed before the cycle begins again." This will be the last solar transit of Venus in our lifetimes. The 2012 event makes the second of a pair, with pairs occurring eight years apart; the previous transit occurred in 2004. Before 2004, the last transit occurred in 1882. The next pair of Venus transits will take place in 2117 and 2125. The rarity depends on an alignment of the planets' orbits, which you can see explained in the infographic below the jump (source here). To see your local viewing time, go here."[W]hen we talk about a transit of Venus, we are talking about a very rare astronomical event indeed (only 81 will occur between 2000 B.C. and 4000 A.D.). This rarity is due to Venus’ nearly circular orbit and its inclination. When the calculations are performed, Venus transits usually come in pairs (like Mercury), but the interval between the second transit of the pair and the next one is generally 122 years."
Image Source: Wiki.
Source SPACE.com: All about our solar system, outer space and exploration
A recent history of Venus transits. Video Source: Youtube.
Astronomers are using information from Venus transits to search for other Earth-like planets beyond our solar system. This is because transits can be detected from great distances and help us to discern if a planet is habitable.
Venus transits have helped in our search for other planets.
Astrologers fit the Venus transit into the 2012 phenomenon. Yes, they've drawn an upside down pentacle in the heavenly alignments in the second picture below. Dark Star Astrology promises emotional upheavals in family, love relationships, addictions, karma and secrets; it also points to more 2012 prophecies:
[T]his transit of Venus is extra special because of a number of other astrological events. We have the strongest influence in over a generation with Uranus square Pluto on June 24. There is the June 4 Lunar Eclipse just a day before, and then for this Venus transit, Venus is retrograde, conjunct minor planet Chaos, and square Mars. I have looked back at the charts of previous transits of Venus, and none had the intensity of this one. I believe that June 2012 will really kick off all the drama that has been predicted in our 2012 Astrology Forecast. There is also mention of the 2012 Transit of Venus in the Cherokee Rattlesnake Prophecy.
Global Astrology predicts earthquakes associated with this transit. Images Source: Global Astrology.