The sun may carry hidden “fingerprints” of a super-Earth-sized planet that it swallowed billions of years ago, according to new research exploring one of the mysteries of our solar system’s early history.

Scientists suggest a planet several times Earth’s mass could have plunged into the young sun, altering its chemical composition and internal structure in ways that may still be detectable today.

The research, published in Monthly Notices of the Royal Astronomical Society , could also help explain discrepancies between conventional models of how our star evolved and its lack of lithium.

Super-Earth May Have Fallen Into The Young Sun

The calculations favor a planet around five to 10 times Earth’s mass — placing the hypothetical lost world firmly in the super-Earth category. Researchers found such a planet might survive its journey through the Sun’s outer layers while losing surprisingly little mass, allowing its material to penetrate deeper into the star.

“Our new study suggests that a planet several times more massive than Earth may have fallen into the young sun and left a lasting chemical imprint deep inside it,” said Professor Mutlu Yildiz, of Ege University in Turkey. “Since planets are made of material that is chemically different from the gas in the disc, we wondered whether the early engulfment of a planet could have left a chemical signature inside the young Sun.”

Evidence For Planetary Engulfment

After modeling the sun’s evolution and comparing the results with precise observations of its interior, the researchers found that the ingestion of a super-Earth could help explain known differences between standard solar models and observations, “including subtle changes in the sun’s internal structure and its depleted lithium abundance,” said Yildiz. “We thought planetary engulfment might affect the solar structure but did not expect the calculations to converge on such a specific super-Earth mass range.”

Where Did The Solar System’s Super-Earths Go?

Super-Earths — defined as planets around five to 10 times Earth’s mass — are common in planetary systems elsewhere in the galaxy, but missing in the solar system. Scientists aren’t sure why. Previous research proposed that super-Earths might once have formed closer to the sun than Mercury before migrating inward through the protoplanetary gas disc — a ring of dense gas and dust that would have orbited the newly formed sun. One or more of these worlds could potentially have spiraled into the young sun.

This research takes that hypothesis even further, asking whether evidence of such a dramatic event might have survived inside the sun for billions of years.

Scientists Could Search For Evidence Inside The Sun

The study does not prove that the sun swallowed a planet, but the evidence — structural and chemical signatures — could be identified using helioseismology (the study of the sun’s internal structure by observing surface vibrations and sound waves). If confirmed, the discovery could not only reveal the fate of a missing super-Earth, but also demonstrate that stars can preserve evidence of planets they destroyed billions of years earlier.

Wishing you clear skies and wide eyes.