One of the first scientific attempts to explain the Star of Bethlehem goes back to the work of Johannes Kepler in the early 17th century. In 1604, Kepler observed a conjunction of planets followed by the appearance of a nova, which led him to propose a similar hypothesis for the time of the birth of Jesus.
Kepler suggested that the Star of Bethlehem might correspond to a triple conjunction of Jupiter and Saturn occurring in 7 BC, in the constellation of Pisces. In ancient astrology, Jupiter was often associated with royalty, while Saturn could be linked to the Jewish people. This configuration could thus have been interpreted as announcing the birth of a king in Israel.
Kepler also considered that this conjunction may have been accompanied by a transient phenomenon, such as a nova, increasing the visibility of the event. Although this second hypothesis is not confirmed by explicit historical sources, it reflects an attempt to link astronomical observation with historical interpretation.
The interest of Kepler’s proposal lies in his approach: he postulates neither a purely symbolic construction nor an arbitrary miracle, but seeks to identify a natural phenomenon that could have been interpreted within a given cultural framework. However, this hypothesis has certain limits, notably because of the chronological gap with a birth situated around 2 BC, and because planetary conjunctions do not visually produce a “single star” remarkable enough to correspond directly to Matthew’s account.
Despite these reservations, Kepler’s work opened the way to a scientific approach to the question and continues to influence contemporary research on the Star of Bethlehem.