What is the transit of Venus?
It might be helpful to start by considering the more familiar phenomenon of a solar eclipse. This occurs when the Moon’s orbit causes it to come between the Earth and the Sun during the daytime, which blocks part or all of the Sun from people’s view. Another word for this sort of event, in which a small astronomical object blocks the view of a larger one, is a “transit”; thus, a solar eclipse could be called a “transit of the Moon.” Similarly, a transit of Venus takes place when Venus comes between the Earth and the Sun, blocking a very small part of it, with the effect being that of a small black dot moving across the Sun. While Venus passes between the Earth and the Sun roughly once every nineteen months, the two planets’ orbits are on slightly different angles. The result is that, to a viewer on Earth, Venus usually seems to pass above or below the Sun. Transits of Venus come in pairs. The last two took place in 1874 and 1882; the next two will be in 2004 and 2012, followed by anoth
