'Fingerprints' inside the Sun could reveal if it once swallowed a planet

A study using MESA stellar-evolution models shows that the Sun’s present-day interior structure and its depleted surface lithium can be reproduced if a planet 5–10 times Earth’s mass was accreted during its early evolution, leaving a lasting chemical imprint. The model simultaneously matches helioseismic sound-speed data, convection-zone depth, and lithium abundance, supporting the hypothesis that a super-Earth survived passage through the solar envelope and was engulfed billions of years ago.