Astronomical transit occurs when a smaller celestial object passes in front of a larger one.
For instance, all inferior planets will cross the face of the Sun at some point in their orbits.
When Mercury transits the Sun, as seen from Earth, the planet may be seen as a dark spot traveling across the Sun’s surface.
In rare cases, one planet can transit in front of another.
The next time this will happen when observed from Earth will be on 22 November 2065 at 12:43 UTC, when Venus will transit in front of Jupiter.
The term star transit is used for the passage of a star through the eyepiece of a telescope.