University of Minnesota
University of Minnesota

Transit of Venus

University of Minnesota

Minnesota Institute for Astrophysics

Thank You!

A big thank you to everyone who joined us for the transit and to everyone who helped make it possible. We had record turn-out for this event with hundreds of visitors. We hope you got the chance to see this once in a lifetime event! The IfA transit viewing wouldn't have been possible without the help of the following people:

Addis Woldesenbet
Mike Milligan
Karley Weir
Corinne Komor
Kyle Neary
Dinesh Shenoy
Kyle Dolan
Eric Bullock
Zahra Forotani
Tom Vonderharr
Terry Jones
Larry Rudnick

Join us for the 2012 Transit of Venus

On June 5th the planet Venus will pass between the Earth and the Sun. In Minneapolis we will be able to view this as a small dot crossing the Sun as the Sun is setting. The Institute for Astrophysics will be hosting a public talk on the transit as well as solar telescopes for safe observing of the event. This will be the last chance to view a transit of Venus until 2117 so don't miss this opportunity! It is important to remember that one should NEVER look at the Sun without proper protection. We are happy to provide telescopes with special filters designed to make viewing this event a safe and pleasant experience. We're hosting a special Public Viewing on

Tuesday June 5th, 2012

which will include an invited talk on the transit.

The talk will be presented even in the case of poor weather, as well as a video feed of the event from Hawaii!

What is a Transit?

A transit is when an object passes exactly between Earth and the Sun and as a result appears as a dark spot traversing the visible face of the Sun. When the Moon does this it can cover the entire Sun and is called a solar eclipse, but it can also happen to the planets Mercury and Venus since they are closer to the Sun than Earth. Even human-made satellites such as the International Space Station can transit the Sun when the geometry is just right. On June 5, it will be Venus crossing the Sun.

A Last in our Lifetime Event

A transit can only occur when an object is both at inferior conjunction and at the "nodes" of it's orbit (i.e. lined up both horizontally and vertically). In the case of Venus, because it orbits almost exactly 13 times for every 8 orbits of Earth—combined with the alignment of the nodes—we see transits of Venus in a pair separated by 8 years, then 105.5 years go by before seeing another 8 year pair, and finally a 125.5 year gap before repeating the cycle again. The last transit of Venus was 8 years ago on June 8, 2004, meaning the next transit after this year will not occur for over 100 years in December of 2117. Even someone born today will be of very old age before this rare phenomenon happens again!

Safely Viewing the Transit

Like an eclipse, viewing the transit involves looking at the Sun and requires special eye protection. NEVER look at the Sun without proper protection: severe eye damage will occur! The retina can be burned even if no discomfort is experienced! The transit can be viewed from any location in North America that isn't cloudy, but at the University we will be offering views through telescopes that will magnify the scene unfolding all while providing the necessary eye protection so you don't have to worry about it.

Should you endeavour to view the transit on your own (though we encourage you to let us do the work for you), please make sure to take the necessary precautions and read about safe methods for solar observing. The linked website discusses eclipse viewing, but all the advice applies to transits (and general solar observing) as well. NASA also provides a similar safe observing guide with denser writing, but is more comprehensive.

Schedule of Events

Please bear with us as we finalize the event times. Times may change slightly after initial posting.

4:00pm–5:00pm - Tate 166
Public Talk

U professor Dr. Terry Jones will be giving an informational talk about the transit just before the event begins.

5:00pm–9:00pm - Tate 450/Roof
Telescope Observing

Telescopes with proper filters for safe viewing will be provided on the roof of the building for the public to look through and see the event. Take the south elevator to floor 4S to reach the roof access through room 450. In the event of cloud cover we will also be streaming live video of the event from Hawaii.

Path of Venus

The transit will proceed as shown in the diagram below by Fred Espenak from NASA's transit website. Times are listed in Universal Time (a modern version of Greenwich Time): subtract 5 hours to translate them into approximate local Central Daylight Time.

[Path of Venus across the Sun]

The event begins at 5:04pm CDT when Venus just begins to touch the Sun (first contact/external ingress). At 5:22pm the entire disk of Venus will have entered the Sun (second contact/internal ingress), displaying the "black drop" effect as it finishes crossing the edge. The halfway point (greatest transit) occurs at 8:26pm just before the Sun sets while only 4° above the horizon. The end of the transit (third and fourth contact/internal and external egress) will not be visible from Minnesota.

A larger PDF version of the above image, as well as other graphs, are available for download at NASA's website.

Getting to Campus

Tate Lab is on the East Bank of the Twin Cities University of Minnesota campus. Information on finding Tate Laboratory and nearby parking can be found here.

For More Information

If you have questions or would like more information about the presentation or observing to be offered by the Minnesota Institute for Astrophysics please feel free to contact our Outreach Coordinator, Jennifer Delgado.