In less than a week, Venus in its orbit will “catch up” to us in Earth’s orbit at one of two places where both orbits are essentially coplanar with the Sun, so the silhouette of Venus will show up against the body of the Sun.
Astronomically, it’s known as a “transit of Venus”. It will start a few minutes after 3:00 pm (local time) on Tuesday, 5 June, 2012, and last past sunset.
It will be another 105 years until this happens again: the planet Venus, in its orbit, passes within one-quarter of a degree of being exactly aligned between the Earth and the Sun, so it can be seen (with protective filtering) in silhouette against the Sun.
People have only seen it happen 7 times before in all of human history, and for almost 240 years it offered the best way to measure the diameter of the Solar System and the universe.
The Arcadia High Science and Physics Dept is planning to have telescopes with sun safe filters for public viewing at the west end of the Arcadia High School Science Building, upstairs on the landing outside the doors.