It's a once in a lifetime event: the June 5th Transit of Venus across the sun. Watch the world wide webcast sponsored by the Coca-Cola Science Center and NASA. | | | IT'S HAPPENING NOW! The 2012 Transit of Venus is underway. Venus's inky black disk will cross the face of the sun, slowly gliding past sunspots and fiery patches of solar plasma, until approximately 0450 UT on June 6th (1150 pm PDT on June 5th). Live webcasts: #0, #1, #2, #3, #4, #5, #6, #7. Realtime Transit of Venus Photo Gallery [Submit your photos] [NASA videos: 2012 Transit of Venus, ISS Transit of Venus] TRANSIT OF VENUS: No one reading this will still be alive the next time Venus crosses the sun in Dec. 2117. That makes today special. On June 5th at 3:09 pm PDT, the second planet begins its historic 7-hour transit of the solar disk. Observers on parts of all seven continents (map) will witness something like this: Photo credit: David Finlay of Sydney, Australia (June 8, 2004). The timing favors observers in the mid-Pacific where the sun is high overhead during the crossing. In the USA, the transit will be at its best around sunset. Creative photographers will have a field day imaging the swollen red sun "punctured" by the circular disk of Venus. Stay tuned to Spaceweather.com's realtime gallery for constantly updated images of the transit. Another photo-stream of interest comes from the International Space Station where Don Pettit will be the first man in history to photograph a Venus transit from space. There are also many live webcasts of the transit from locations around the world: #1, #2, #3, #4, #5, #6. (Submit more webcast links here.) Spaceweather reader Eric Allen of Trois-Rivieres, Quebec, has combined an image of today's sun with NASA's predicted transit path: "I created this transit 'finder chart' to know where to look for first contact," explains Allen. "That is where the Mysterious Arc of Venus might appear." Realtime Transit of Venus Photo Gallery [Submit your photos] [NASA videos: 2012 Transit of Venus, ISS Transit of Venus] Observing Tip: Do not stare at the sun. Venus covers too little of the solar disk to block the blinding glare. Instead, use some type of projection technique or a solar filter. A #14 welder's glass is a good choice. Many astronomy clubs will have solar telescopes set up to observe the event; contact your local club for details. Transit of Venus Web Links: BEFORE THE TRANSIT: As Venus approaches the sun, it turns its nightside toward Earth. This turning transforms Venus into a rarely-seen thin ring of light. Lorenzo Comolli photographed the phenomenon from Tradate, Italy, on June 4th: The effect is caused by particles in upper layers of Venus's atmosphere which scatter sunlight around the circumference of the planet. The ring is very difficult to observe, and often only black-belt astrophotographers are able to record the phenomenon. "This picture was taken while Venus was a scant 2°17' from the sun's center, and it was very difficult to obtain due to the extreme proximity of the solar limb," says Comolli. "Extreme care was due to avoid the sun light entering the telescope. The extension of the crescent to form a nearly complete ring was remarkable on June 4, while nearly invisible on June 2. Another interesting observation is the limb brightening in Venus's southern hemisphere between 50° to 70° latitude. For confirmation, I obtained a second image using a W25 filter (red) that shows the presence of the brightening in the same way." more images: from Tobias Kampschulte of Gennadi, Rhodes, Greece; from Steve Miller of Lake Havasu City, Arizona: from Antonios Pantelidis of Florina, Greece; from Rob of Liverpool, UK; from Elias Chasiotis of Markopoulo, Greece; from Pavol Rapavy of Observatory Rimavska Sobota, Slovakia; from Ernie Mastroianni of Milwaukee, Wisconsin; from Joe Mcbride of Grand Rapids, Michigan Potentially Hazardous Asteroids ( PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time. On June 5, 2012 there were 1293 potentially hazardous asteroids. Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach. | The official U.S. government space weather bureau | | The first place to look for information about sundogs, pillars, rainbows and related phenomena. | | Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever. | | 3D views of the sun from NASA's Solar and Terrestrial Relations Observatory | | Realtime and archival images of the Sun from SOHO. | | from the NOAA Space Environment Center | | the underlying science of space weather | |