Illustration of Heliosphere Models (IMAGE) NASA/Goddard Space Flight Center Caption New data from NASA's Cassini, Voyager and Interstellar Boundary Explorer missions show that the heliosphere -- the bubble of the sun's magnetic influence that surrounds the inner solar system -- may be much more compact and rounded than previously thought. The image on the left shows a compact model of the heliosphere, supported by this latest data, while the image on the right shows an alternate model with an extended tail. The main difference is the new model's lack of a trailing, comet-like tail on one side of the heliosphere. This tail is shown in the old model in light blue. Credit Dialynas, et al. (left); NASA (right) 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.