The William M. Staerkel Planetarium will host a viewing of the transit of Mercury, the rare occasion where Mercury appears to move in front of the Sun, on Monday, Nov. 11.
The planetarium will join the Champaign–Urbana Astronomical Society (CUAS) in setting up telescopes for the public throughout the morning. weather permitting; the transit will be visible from just after sunrise until 12:07 p.m.
Transits occur when planets pass directly between Earth and the Sun. This can only happen with the planets closer to the Sun, Mercury and Venus. Since the Sun is much larger than either of them and they are much farther than the Moon, they make a small silhouette on the Sun's disk instead of eclipsing our star. Transits of Venus are very rare; two occurred in 2004 and 2012, but the next one will happen in 2117.
Since Mercury is closer to the Sun, transits are a little more common. A transit of Mercury was visible in Champaign in 2006 and in 2016. However, the next one we can see from Illinois will be in 2049, so this Veterans Day will be the last chance to see such an event for a while.
Please note that this is a solar observing event, not a planetarium show. Observing the Sun requires special filters, and Mercury is too small to see the disk without a telescope. The planetarium and the CU Astronomical Society will set up telescopes designed to observe safely. When observing the Sun, you may also see a sunspot or a prominence, but it is unlikely, since the 11-year cycle of sunspot activity has reached a minimum.
The planetarium offers ample parking and a lobby where residents can warm up if the morning temperatures are cold. Participants should park in the M1 parking lot and dress in layers. Call the planetarium at 217/351-2567 for updates to the viewing if the weather seems uncertain.
[image from nasa.gov]