Could the Star of Bethlehem Have Been a Comet? New Analysis Reexamines a 5 B.C.E. 'Broom Star'

Could a Comet Explain the Star of Bethlehem?

Astronomers and historians have long debated natural explanations for the biblical Star of Bethlehem — the brilliant object said to have guided the magi to the newborn Jesus. One enduring hypothesis points to a planetary conjunction (for example, Jupiter with Saturn), but a new analysis argues a different candidate: a comet.

The proposal. On December 3, Mark Matney, a planetary scientist who works at NASA and conducted the work independently of the agency, published a paper in the Journal of the British Astronomical Association. Matney revisits Chinese astronomical records from 5 B.C.E. that describe a “broom star” (a historical term often used for comets) and suggests a long‑period comet from the distant Oort Cloud could account for the traditional narrative.

How a comet could 'stand still'. Matney proposes that if a comet passed extremely close to Earth — on the order of the Moon’s distance — its apparent motion across the daytime sky could be unusually slow. In such a geometry the comet’s projected motion might appear to halt or linger for hours, producing the impression described in some retellings of the magi’s observation.

“A comet could stay in one place if it was basically on a ‘collision course’ with Earth,” Matney says. “That's exactly what you would expect of an object that's going to pass very, very close to the Earth.”

Conflicting evidence and alternative interpretations. The Chinese accounts are not straightforward. Some translations indicate the object remained in a single constellation for roughly 70 days — a duration many researchers argue is far too long for a typical comet and more consistent with a bright nova. Matney counters that an exceptionally close comet on an unusual trajectory could appear to linger in one part of the sky for an extended period, which he says keeps the comet hypothesis viable.

Other scholars urge caution. Ralph Neuhäuser, an astrophysicist at Friedrich Schiller University Jena who studies historical astronomical records, notes that older sources are often ambiguous or sparse and therefore can mislead modern interpretations. Some researchers also question whether searching for a direct astronomical counterpart to a theological narrative is a productive enterprise.

Conclusion and context. Matney acknowledges the limits of the surviving records and frames his paper as a contribution to “forensic astronomy” rather than a definitive identification of the Star of Bethlehem. As Frederick Walter, an astronomer at Stony Brook University, puts it: this work is unlikely to be the final word but represents a worthy addition to the debate.

Additional reporting by Clara Moskowitz.