When Venus passes directly between Earth and the Sun, it appears to observers as though a small disk is moving across the face of the Sun. Before the space age, such transits helped scientists calculate the distance between Earth and the Sun. Among the rarest of predictable astronomical phenomena, transits of Venus currently occur in a pattern that repeats every 243 years, with pairs of transits 8 years apart separated by gaps of 121.5 and 105.5 years. When will the next transit of Venus occur? Discuss
Source: The Free Dictionary