Gliese 12 b size comparison (IMAGE) Royal Astronomical Society Caption Gliese 12 b’s estimated size may be as large as Earth or slightly smaller — comparable to Venus in our solar system. This artist’s concept compares Earth with different possible Gliese 12 b interpretations, from one with no atmosphere to one with a thick Venus-like one. Credit NASA/JPL-Caltech/R. Hurt (Caltech-IPAC) Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.