HAA Skywatch

On June 5, 2012, there will be a rare celestial event - the transit of Venus. A transit is when an object passes in front of another, in this case, the planet Venus will pass in front of the Sun. The last time this occurred was in 2004 and it won't happen again until 2117. So this will likely be the last chance to see this event during your lifetime.

For our area (southern Ontario), we won't see the entire event. It will begin around 6pm and will end while the transit is mid-way complete at sunset. But the 2-3 hours visible from our area will provide plenty to see. The most spectacular parts of the transit are mostly at the beginning (ingress) and at the end (egress). During ingress and egress (the latter egress will not be visible from our area since it will occur after sunset) provides an opportunity to see something called the black-drop effect where the black dot of Venus appears to pull the surface of the Sun (or the Sun pulling on the surface of Venus) drawing the sharp edge into a "drop" effect. Fortunately this is potentially quite visible from our area.

Special Note: Please do not look directly at the Sun either with your eyes or through any device such as a camera, binoculars or telescope without proper safety filters. The strong sunlight can cause permanent eye damage without adequate protection. There are properly approved solar observing glasses available or safe filters you can purchase to protect you. Alternatively you can also use a pinhole camera to project this transit safely onto a white sheet of paper. Plans for these can be found on the internet.

The HAA does not have any official plans to observe the Venus transit on June 5. Many of our members will be traveling to locations outside of our area to better view this rare event. However there are other groups in our general area which will be hosting special public viewing sessions. We encourage you to look up these activities and view this once in a lifetime event. They will all have safe equipment for viewing the event and most will have free solar glasses. Check out these websites for more details. There may be other events so check the internet and your local newspapers.

The closest to our area is McMaster University and McCallion Planetarium. They will be holding a large event on their campus:
http://www.physics.mcmaster.ca/planetarium/

The Dunlap Institute and the University of Toronto will be holding an event at Varsity Stadium:
http://universe.utoronto.ca/special/transit2012

The Ontario Science Centre will be hosting their own event:
http://www.ontariosciencecentre.ca/calendar/default.asp?eventid=1206

University of Guelph will be holding an event on their campus:
http://www.uoguelph.ca/events/2012/06/transit_of_venus_planetgazing.html

As will University of Waterloo:
http://waterlootransitofvenus.eventbrite.com/?ebtv=C

Several of the regional chapters of the RASC will be holding events in the area:
Mississauga (UofT Erindale campus) - http://mississauga.rasc.ca/
Niagara (Port Dalhousie) - http://astronomyniagara.com/

If you were in Northern California or Nevada, you would have an opportunity to see an Annular Solar Eclipse. This is an event when the Moon passes in front of the Sun. But the Moon is at or near Apogee, which is the furthest it gets in its elliptical orbit around the Earth so it appears a bit smaller and doesn't quite completely cover the Sun leaving a thin ring of light (the Annulus).

If you're not fortunate enough to be located there, you can still see a partial eclipse from most of the Western and Central regions of North America. However the visible duration of the eclipse is reduced more as you move further East. Sadly those along the East coast won't see anything as the Sun will have set before the eclipse occurs.

For those of us in Southern Ontario, we do have a chance to see a small portion of this event. Sun will set during the eclipse so we might only see the beginning of it.

First a Warning: Never look directly at the Sun, even near sunset, without proper safety eye protection. This means using an approved solar filter or perhaps a #14 welders lens. Failure to heed these precautions could result in permanent eye damage. Another option is pin hole projection: one piece of paper with a pinhole held in front of another used as a screen. You can sometimes use the shadows of leaves in this fashion - though the shadows may be rather long due to the late time of day.

Since this event is going to occur near sunset and we won't have much time, to maximum that little time, try to get as far West as you can and overlook water or a very low horizon. Also a mountain cliff could work. You want to minimize the obstructions on the horizon as much as possible. Look West (compass bearing 287 degrees from our area) and follow the Sun as it sets. It will begin approx 8:20pm from our latitude and end when the Sun sets at about 8:35pm.

The following is a chart showing the path of the eclipse and the areas which will see a partial eclipse. Click on image to see larger version.

NASA also has an interactive Google Map here which can give some information. It mostly shows the path of the total eclipse, not the partial areas. But it does provide start times for other areas - it just doesn't indicate when sunset occurs and the end of your viewing. Note: this site is a bit slow due to volume.

Our Facebook page also has a link to the Sky&Tel's website which has links to more information.

At the time of this posting, the forecast for area is expected to be clear on Sunday. Please enjoy safely.