Planetary occultations are astronomical events in which a planet passes in front of a star, temporarily blocking the star's light from reaching Earth. During these events, astronomers can observe the planet's atmosphere and surface features, as well as measure the planet's size and shape. This type of observation
From Wikipedia
In astronomy, planetary transits and occultations occur when a planet passes in front of another object, as seen by an observer. The occulted object may be a distant star, but in rare cases it may be another planet, in which case the event is called a mutual planetary occultation or mutual planetary transit, depending on the relative apparent diameters of the objects.