A new preprint by researchers at the University of California, Riverside examines how a planet’s size affects its ability to retain an atmosphere, a key factor for habitability. Both outlets report that the study focuses on the lower size limit for planets that could plausibly develop and sustain life. The model suggests that there is a minimum planetary mass and/or size below which a planet is less likely to hold onto its atmosphere over time, reducing the prospects for stable, life-supporting conditions. According to the summary of the findings, planets only slightly smaller than Earth are likely near the smallest viable size for habitability. The work is presented as a theoretical tool to help prioritize exoplanet targets, especially given limited telescope time. By identifying where the boundary for atmospheric retention may lie, the study aims to narrow the search for potentially habitable worlds and guide observational efforts toward planets most likely to meet the physical requirements for life.