Last time in your Lifetime: Venus Transit's the Sun

Star Circle Academy
Star Circle Academy
Public group

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COST: Free

This is an "unhosted event"

This is the last chance you have in your lifetime to watch Venus transit the sun - unless you live until 2117, that is.

The tiny Venus will be crawling across the face of the sun as it nears sunset. The transit begins at 3:06 PM and ends at 9:47 PM, an hour and 20 minutes after sunset - so the end won't be visible from the Western US. At 3:06 PM when the transit begins the sun is 61 degrees high in the sky toward the South, Southwest (248 degrees az). At 8:27 the sunset will be toward the NNW (300 degrees).

BEWARE: Do not look at the sun without using welding glass or properly prepared optics. A hydrogen alpha filter may reveal both the planet and more details in the sun.

Owing to the rarity of the event I have a list of alternative locations that may change at the last minute due to weather. It will be extremely difficult to coordinate that among more than one or two people so I've made this an "un hosted" event.

Here is a fantastic resource for understanding and planning for the Venus Transit:

Click above for the full app.

You'll need the following:

A telephoto lens. Don't ask "how long" rather think "as long as I can get!" Anything up to 2300 mm is a good choice (or longer!) A solar filter for your lens/telescope. See this article ( However if you're planning to do high magnification you will want a well built glass version or a very crisp Baader Astrosolar version. A super steady tripod. [optional] an Equatorial mount that can track at the solar rate. A wearable or holdable solar filter. [optional] Intervalometer Clear view of the western sky - preferably all the way down to sunset. [not optional] Clear weather!

Expect to see sunspots in your photo, too. Look carefully of this image shot through the clouds. That curious looking "TIE Fighter" is indeed the International Space Station.

The "dot" of venus crossing the sun will be larger.

Places to GO to see the Transit (though where ever you are should work if you already have solar shades).

Mount Diablo Astronomical Society

<... click for weather forecast.

Tue 6/5/2012 2 PM - 9 PM
Venus Transit Viewing Juniper Campground, Mount Diablo Juniper Campground entrance, Clayton, CA Setup 1 PM More details ( Tue 6/5/2012 2 PM - 7 PM
East Bay Parks Shadow Cliffs Venus Transit viewing, East Bay Parks Shadow Cliffs , Pleasanton, CA Setup 1 PM More details ( Tue 6/5/2012 3 PM - 8 PM
Lafayette Library Venus Transit, Lafayette Public Library, Lafayette, CA Setup 2 PM More details ( Other Locations

Chabot Space and Science Center ( (entry fee)
Foothill College (, Los Altos (free, $3 parking)
Mount Hamilton Lick Observatory ( (sold out) Your backyard (free, no parking or entry fee)


Exploratorium / Mauna Loa ( Webcast SLOOH Event (