On Monday, May 9, there is a somewhat rare celestial event β the transit of Mercury across the sun. Mercury is the nearest planet to the sun and stays close to the sun all the time. Every once in a while, it passes directly in front of the sun and becomes visible as a small, black disk silhouetted against the bright sun.
The transit will be in progress as the sun rises at 5:30 a.m. in Tucson. Mercury reaches its deepest incursion across the sun at 7:57 a.m. and exits from the sun at 11:52 a.m. This is an absolute must-see event. The next transit of Mercury will not occur until 2019.
You will need a telescope to see Mercuryβs tiny disk. It is absolutely necessary that the sun be observed with a safe solar filter or by safe protection methods. See the following website for more safety information on how to view the sun:
eclipse.gsfc.nasa.gov/SEhelp/safety.html
Very inexpensive solar filters for telescopes or visual observing can be purchased online or at science centers, museums, and astronomy shops, such as Flandrau Science Center & Planetarium (621-7827), Starizona (292-5010), and Stellar Vision (571-0877). Many organizations probably will be participating in free public viewing of the transit. I recommend you also check with the Tucson Amateur Astronomy Association, Inc. at tucsonastronomy.org and the Flandrau Science Center for more information.
