The transit of Venus, in which Venus passes between the Earth and the Sun, occurs in couplets eight years apart. These couplets don't return for another century. If you miss them, you miss them forever. In 1760, astronomer Matthew Sangster leaves his family in Dublin to observe the transit of Venus from India. Despite vowing to return within three years, Matthew's journey is perilous. Delayed by events at sea, the deserts of Arabia,...