Star of Bethlehem mentioned in Bible was a bright comet, says NASA scientist

In the Gospel of Matthew, the star is described as rising “in the east,” moving ahead of the travellers on the short road from Jerusalem to Bethlehem, and then appearing to “stand over” the place where Jesus was born. Such behaviour is not typical of stars or planets, a riddle that has led many to view the account as symbolic or miraculous.

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Matney, however, suggests that the answer may lie in a comet recorded in Chinese imperial archives, which was visible for more than 70 days in the spring of 5 BC. The timing is significant: historians generally place Jesus’s birth between 6 BC and 5 BC, in part because Herod the Great, who appears in the biblical narrative, died no earlier than late 5 BC.

Using a new modelling technique, Matney reconstructed possible orbits for the Chinese comet based on the ancient observations. One particular set of trajectories showed that the object could have passed unusually close to Earth, close enough that, for a brief period, its apparent motion almost cancelled out Earth’s rotation.

Modern satellite engineers refer to this as “temporary geosynchronous motion.” From the ground, the comet could have appeared to pause overhead for a short time before continuing on its path.

In one of Matney’s models, this pause would have occurred on a June morning in 5 BC, with the comet positioned almost directly along the route from Jerusalem to Bethlehem. Travellers heading south could have watched the bright object rise before them, seemingly leading the way, and then hovering overhead as they reached their destination.

“This is the first astronomical candidate for the Star ever identified that fits Matthew’s description, a star that ‘went before’ the Magi until it ‘stood over’ the place where Jesus was,” Matney writes.

A comet which passed close to earth

For the effect to work, the comet would have needed to pass at a distance of about 236,000 to 249,000 miles (380,000–400,000 kilometres) from Earth, roughly the distance between Earth and the Moon. Such close encounters, Matney notes, are rare but not impossible. He points to the 2014 Siding Spring comet, which swung within 87,000 miles (141,000 km) of Mars, far closer than the Moon’s distance from Earth.

A comet passing so close to Earth would have been spectacularly bright, potentially visible during the daytime. Matney believes the Magi could have seen it rising in the southern sky late in the morning, a striking and unmistakable sight during their journey.

The idea also aligns with ancient beliefs. Throughout Greco-Roman and Eastern traditions, comets were interpreted as omens of royal births, political upheaval or divine intervention. A long-lasting, brilliant comet could easily have compelled elite astrologers to undertake a long journey.

Nevertheless, Matney’s analysis does not close the debate. More than 400 scholarly interpretations of the Star of Bethlehem have been proposed over the centuries. The famed astronomer Johannes Kepler once suggested a rare conjunction of Jupiter and Saturn in 7 BC. Others have argued for a supernova, a dramatic stellar explosion. And many remain convinced that the star was never intended to be understood as a natural phenomenon at all.

For now, Matney’s comet hypothesis adds a new, scientifically plausible chapter to one of history’s most enduring mysteries—one that blends astronomy, ancient records and a story cherished by billions.