Within 3 weeks of each other, 2 celestial objects will pass in front of the Sun -- the Moon, and then Venus! There will be a partial solar eclipse on May 20th, and a "transit of Venus" on June 5th. If the weather cooperates, they will be exciting observing opportunities, but you'll need to know where, when, and how to witness these gatherings.
Where? (northwestern horizon)
Both of these events involve the Sun, take place late in the day, and will be observable until sunset. Therefore, you'll need to find a location to observe from where you can see close to the horizon where the Sun sets this time of the year -- northwest.
When? (times listed for the Madison, Wisconsin general area; CDT)
- Partial Solar Eclipse: Sunday, May 20th, 7:21 PM to sunset at 8:20 PM The Moon will start to pass in front of the Sun, as viewed from Madison, Wisconsin (USA), at 7:21 PM CDT, on May 20th. The maximum eclipse for us will occur at 8:18 PM, where the Moon will cover 58% of the Sun's disk. The eclipse will still be taking place when the Sun sets. For some Pacific observers, this eclipse will be an Annular Eclipse, which means that the entire disk of the Moon will pass in front of the Sun, but the Moon is too far away from the Earth to block the entire face of the Sun.
- Transit of Venus: Tuesday, June 5th, 5:04 PM to sunset at 8:34 PM Venus will begin to pass in front of the Sun at 5:04 PM CDT for us in the Madison, Wisconsin (USA) area. A "transit of Venus" is truly an historic event! In the 17th and 18th centuries, Venus transits like this were used to estimate the distances to the planets. On a personal note, when one celestial object passes in front of another, it gives you a sense of depth to the cosmos -- otherwise, we have a hard time perceiving which objects in the sky are close and which objects are farther away. This is our last chance to see a transit of Venus in our lifetime! The next one will occur in 2117.
How? (you must have a way to safely view the Sun)
Even if the Moon is blocking our view of part of the Sun, the Sun is too bright to look at! Don't even try! But here are a couple of safe viewing techniques.
- Eclipse Shades: (inexpensive "glasses" that block 99.9% of the Sun's light)
You can buy these through the MMSD Planetarium and the Memorial HS Astronomy Club for $2 (fundraiser for the planetarium).
- Pinhole Camera Projection Technique: (use white tagboard, foil, scissors, and tape) Use a pin to poke a tiny hole in a piece of aluminum foil. Tape the foil over a hole in one piece of tagboard, and project the sunlight passing through the tiny hole onto another piece of tagboard -- it will produce an image of the Sun. This works fine for the eclipse, but not the transit.
Public Observing Events: (we'll bring solar telescopes and eclipse glasses)
The Madison Metropolitan School District Planetarium will be hosting an observing event for the solar eclipse and the transit. The events are FREE, but eclipse glasses are $2 while supplies last. Join us for the entire event or just for 15 minutes! Both events are weather dependent. Cancelation notices will be posted on the planetarium's web page, Facebook page, Twitter feed, and voicemail message (608-663-6102).
Please park in the street (curb-side parking). Bathrooms and snack shop available inside Keva.
- Eclipse: May 20th, 7:00-8:30 PM
- Transit: June 5th, 4:45-8:30 PM