Orbits of Planets in Gliese 581 System Compared to Our Own Solar System (image) National Science Foundation Share Print E-Mail Caption The orbits of planets in the Gliese 581 system are compared to those of our own solar system. The Gliese 581 star has about 30 percent the mass of our sun, and the outermost planet is closer to its star than the Earth is to the sun. The 4th planet, G, is a planet that could sustain life. Credit Zina Deretsky, National Science Foundation Usage Restrictions None Share Print E-Mail 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.