Beginning on June 5, for a period of about seven hours, the planet Venus will pass directly in front of the sun as seen from Earth. This is the long-awaited transit of Venus, whereby this world appears as a small, dark dot sailing along in front of the solar disk. The June 5-6, 2012 transit will be the last transit of Venus in this century. ~ EarthSky Tonight
Do not miss this once in a lifetime event. Learn what you can from the EarthSky site & then hop over to NASA's Sun-Earth Day 2012 site. There you will find all the materials necessary to teach yourself (or students) about the transit, including a live webcast from Mauna Loa, Hawaii.
(photograph collage via NASA/LMSAL)