The question of what the Star of Bethlehem actually was has intrigued astronomers and historians for over two millennia. While traditional theories often point to planetary conjunctions or supernovae, recent research has brought the Comet Theory back to the forefront.
New findings published in December 2025 by NASA planetary scientist Mark Matney suggest that a comet recorded by ancient Chinese astronomers in 5 BC may be the only astronomical object that fits the specific, "bizarre" movements described in the Gospel of Matthew.
1. The Historical Record: The "Broom Star" of 5 BC
The strongest evidence for the comet theory comes from the Han Dynasty in China. Ancient Chinese court astronomers were meticulous record-keepers, viewing celestial events as vital political omens.
The Observation: In the "Book of Han," records show a "guest star" (likely a comet) appearing in the constellation Capricornus during the second month of the second year of Emperor Ai (March–April 5 BC).
The Duration: This object remained visible for 70 days. Such a long period of visibility is characteristic of a major comet rather than a meteor or a supernova, which usually behaves differently in the historical record.
The Description: It was described as a hui-hsing or "broom star," a term typically reserved for comets with visible tails.
2. Solving the "Standing Over" Mystery
A major stumbling block for the "Star of Bethlehem" is the biblical description that it "went before" the Magi and then "stood over" the place where the child was. Most stars and planets move too slowly or predictably to appear to "lead" a traveler in a specific direction.
Temporary Geosynchronous Motion
Matney’s 2025 research utilized numerical modeling to show that if this 5 BC comet passed exceptionally close to Earth—roughly the same distance as the Moon—it could have created an optical illusion called temporary geosynchronous motion.
Leading the Way: As the Magi traveled south from Jerusalem to Bethlehem, a comet on a specific trajectory could appear to move ahead of them in the sky.
The "Stop": For a period of about two hours, the comet’s orbital speed and the Earth’s rotation could have matched perfectly. To an observer on the ground, the comet would appear to come to a dead stop and "hover" directly overhead.
3. Comets: Bad Omens or Royal Heralds?
A common argument against the comet theory is that ancient cultures almost universally saw comets as bad omens—harbingers of death, war, or the "sweeping away" of old regimes.
However, the Magi were likely Zoroastrian astrologers from Persia or Babylon. For them, a comet "sweeping away" an old order could be interpreted as the birth of a new King who would change the world. Furthermore, the Roman world sometimes viewed comets as "stars of the soul," such as the famous comet of 44 BC which was believed to be the soul of Julius Caesar ascending to heaven.
4. Comparing the Candidates
While the comet theory is compelling, it competes with other scientific explanations:
| Candidate | Date | Pros | Cons |
| Comet (5 BC) | 5 BC | Matches Chinese records; can "move" and "stop." | Usually seen as a bad omen; rare close approach required. |
| Planetary Conjunction | 7–2 BC | Predictable; involves "King" planets (Jupiter/Saturn). | Planets don't "stop" over a single house; not "new." |
| Supernova | Unknown | Extremely bright; can be seen in daylight. | No surviving supernova remnants found from that era. |
5. The Scientific Challenges
Despite the excitement around the 5 BC comet, there are still missing pieces to the puzzle:
Lack of Corroboration: Aside from Chinese and Korean records, there are few contemporary accounts from Rome or Greece that mention a spectacular comet in 5 BC.
Geological Evidence: A comet passing as close as the Moon would likely have left a "dust signature" in the Earth's atmosphere. Researchers are currently looking at ice cores from Greenland and Antarctica to see if there is a spike in cometary dust dating to 5 BC.
Summary
The 5 BC comet remains one of the most scientifically plausible explanations for the Star of Bethlehem because it is the only candidate that can account for the specific navigation and halting described in historical texts. Whether it was a natural event or a miracle remains a matter of faith, but the astronomical data confirms that a "broom star" did indeed haunt the skies during the window of Jesus’ birth.
Would you like me to look into the specific astronomical records from other ancient civilizations, like the Babylonians, to see if they mentioned this 5 BC event?