Image (IMAGE) Siberian Federal University Caption A scientist from Siberian Federal University (SFU) and his colleagues from Austria and Germany constructed a physical and mathematical model of Mars- and Venus-sized planet formation. The team concluded that Mars had no chances to develop a thick atmosphere and biosphere. In the case of Venus it depended on solar activity: according to the scientists, it managed to keep its atmosphere due to the fact that young Sun was not very active. Credit Nikolai Erkaev Usage Restrictions None License Licensed content 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.