The term transit, in astronomy refers to events where one celestial object passes directly in front of a more distant celestial object and when the nearer celestial object appears smaller than the more distant object.

A transits is an apparent phenomena and is one of the three know types of occultation.

An occultation in astronomy is an event when one celestial object passes directly in front of another celestial object during which the foreground object blocks from view (occults) the background object, either partially or entirely.

An occultation can be either [1] a partial occultation as in a transit, [2] a total occultation, where the foreground object appears larger and completely hides the background celestial object from the observers view, or [3] a occultation which results in casting a shadow on the observer as in an eclipse.

In astronomy, a transit (or astronomical transit) is the passage of one celestial object directly between a larger celestial object and the observer. As viewed from a particular vantage point, the transiting body appears to move across the face of the larger body, covering a small portion of it.

The transits of Venus are among the rarest of predictable celestial phenomena and always occur in pairs, eight years apart, which are themselves separated by more than a century: The previous transit of Venus took place on 8 June 2004.