Super Earth May Have Been Swallowed by the Young Sun, Study Finds

A super earth may have met a violent end billions of years ago when the young Sun swallowed a planet several times more massive than our own world, according to new research. Scientists say the event could help explain unusual features inside the Sun and why the solar system has no known planet of this type today.

The research, published Sept. 10 in the Monthly Notices of the Royal Astronomical Society, used computer modeling of the Sun’s evolution to investigate whether a planetary engulfment could account for longstanding differences between solar models and observations.

A Missing Planet May Explain Solar Mysteries

Super-Earths are planets more massive than Earth but not necessarily as large as the ice giants in our solar system. They are common in other planetary systems, making their absence from our own system an enduring question for astronomers.

Researchers led by Mutlu Yildiz of Ege University in Turkey examined whether a super-Earth could have formed in the young solar system and later migrated inward through the protoplanetary disk surrounding the infant Sun.

Their models found that the scenario providing the best match to the Sun’s present characteristics involved a planet with a mass between five and 10 times that of Earth. The planet could have moved through the Sun’s outer layers before ultimately dissolving inside the star.

Scientists Look for Evidence Inside the Sun

The proposed planetary ingestion could help account for discrepancies involving the depth of the Sun’s convection zone and the speed of sound beneath it. It may also offer an explanation for the Sun’s unusually low surface abundance of lithium.

The idea is based on the fact that planets form from material that is chemically different from the gas surrounding a young star. If a planet entered the Sun, researchers reason that it could have left a chemical signature within the star’s interior.

However, the researchers have not established that the Sun definitely consumed such a planet. The current evidence comes from computer modeling and unexplained characteristics of the Sun, and other explanations for the solar discrepancies remain possible.

The next step is to determine whether the predicted structural and chemical fingerprints can be independently detected through observations of the Sun.

If those signatures are found, they could provide evidence that a super earth once existed in the young solar system before disappearing into the star that now anchors it.