Transit of Venus: Tuesday, June 5th, 2012

Warning: Never directly view any sun-related phenomenon without using adequate eye protection. See more on this below. The blog officially advises against any attempts at viewing this event directly, and recommends restricting one’s ‘observations’ to online or news resources, only.

The annular solar eclipse of May 20th was a bit of a bust for those of us outside its viewing area. However, Mother Nature will be providing us with an even more significant celestial event on Tuesday, June 5th, 2012: A rare transit of the planet Venus across the face of the sun. For those of us in the eastern United States, the transit begins just before sundown, at approximately 6PM EDT.

Venus Transit 2004

Venutian Transit of 2004 (source: Wikipedia Commons)

Venutian transits are extremely rare. They occur in “pairs”, separated eight years apart, with 121 years passing before the next pair occurs. And pairs alternate between June and December. The first transit of the current pair happened eight years ago, in June, 2004, with the second (and last) transit occurring this coming Tuesday. The next transit will not happen until December of 2117.

Normally, Venus spends about 9 months of a given year as an evening star (Hesperus; appearing after sunset), then transitions to a morning star (Phosphorus; appearing before sunrise) for another nine months. During its transition from one phase to the other, Venus either crosses in front of the sun (inferior conjunction), or passes behind the sun (superior conjunction).

The transit is simply an inferior conjunction where Venus is not just in front of the sun, but on a trajectory between the sun and earth. It’s essentially an eclipse; only, unlike a solar eclipse by the moon, the apparent size of Venus is far too small to block large portions of the sun from view. Since Venutian transits are so rare, we all should consider ourselves fortunate to be living in a century experiencing a transit-pair.

Venus Transit Solar Paralax

(source: Wikipedia Commons)

If you plan to view this event (and you proceed at your own risk, if you do), adequate eye protection is essential. A #14 welder’s glass, or an equivalent sun filter on your telescope or binoculars (and in either case, acquired from a trustworthy source) is required. And even though you’re using adequate eye protection, also limit your viewing time to just a few seconds. If you don’t have adequate eye protection, avoid it altogether, and be satisfied with the multitude of photos that you know are going to be published on the Internet, anyway. A telescope isn’t necessary to see the Venutian transit, but keep in mind that you’ll be looking for a tiny dark spot in front of a sphere that’s about the same apparent size as the full moon.

Popular Live Feeds (Active Now at 8:44PM EDT)

MSNBC Video: NASA TV’s coverage of the Venus Transit.

Venus Trans from Keck Observatory, Hawaii.

Venus at the moment of third contact (Keck Observatory)

Live streaming of the transit of Venus from the Keck Observatory (Hawaii), just at the moment of third contact.

More Information on Safe Viewing and Other Resources

Six ways to see the transit of Venus safely (via )

The Transit of Venus in Google Earth ( via Google Earth Blog )

For an excellent account of the Venutian transit, and an explanation of how transits are leveraged in the discovery of new exoplanets, I highly recommend the following article by John Rennie of Smart Planet.

The Old Farmer’s Almanac’s Monthly Sky Watch contains some great resources, times, and sky maps for the transit. (Note that this page will most likely be recycled after June ends).

On Twitter#venustransit seems to be the hash tag of choice. Track this one. You’ll probably find both amateur and professional astronomers and other sources posting tweets with images or links to this hash tag, during and after, the actual transit.

So happy viewing to all….And remember: No adequate eye protection, no viewing!

About John Poole

My interests include historic homes, architectural preservation and restoration, improving the energy performance of old houses, and traditional timber frames.
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2 Responses to Transit of Venus: Tuesday, June 5th, 2012

  1. John Poole says:

    Had a conversation with the guys at my local welding supply shop yesterday, and they said they’ve been sold out of #14 shades for many days now. One noted that #14 is not a commonly used shade, so they don’t stock too many and ran out quickly. And no one else seems to have them. The other related bright “flashes” he used to experience in the middle of the night from staring at an arc welder for too long a period, even with proper glass, and concluded viewing solar phenomenon was equally risky. They then asked me about the mechanics of the transit, which they took quite a bit of interest in.

  2. John Poole says:

    No, in this case, rose-colored glasses most definitely will not work!

    But a welder’s helmet with a #14 glass, and perhaps rose decals elsewhere, will definitely work.

    Oh, and it’s next Tuesday, not Monday. Nice thing about your time zone is this occurs in the middle of the afternoon, too.

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