In astrology, the term “correspondences” refers to the connections between the macrocosm (or the universe) and the microcosm, such as individual people or even parts of the body. In this belief system, there are also correspondences between celestial bodies—such as between Mars and the zodiac sign Aries—that are reflected in the relationships between people. As the celestial bodies move around in the universe, they have a corresponding impact on people’s lives, characters, and relationships. This belief system underpins the entire plot of The Luminaries, as is shown by the astral charts at the beginning of each section of the novel.

The key astrological correspondence in The Luminaries is the relationship between Anna and Staines. When Lydia learns that Anna and Staines were both born in Sydney on the very same day, she notes to Anna that she “may have an astral soul-mate, whose path through life perfectly mirrors [her] own” (716), showing that their time and place of birth connects them on an astral level. Lydia even uses the term “correspondences” to characterize the similarities between the two characters and their deep connection with one another. Anna and Staines appear to have an instant affinity for one another when they meet on the deck of the ship from Sydney to Dunedin.