Saturn's Moon Titan (IMAGE) University of Maryland Caption A new research paper describes a period more than 2.4 billion years ago, when Earth's atmosphere was filled with a thick, methane-rich haze much like Saturn's moon Titan, seen here in an image taken by NASA's Cassini spacecraft in 2013. Credit NASA/JPL-Caltech/Space Science Institute 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.