3D model of WR140 shells after 18 orbits (IMAGE) University of Sydney Caption 3D model of WR140 shells after 18 orbits (or 144 years) of cyclic dust formation Credit Yinuo Han/Peter Tuthill/Ryan Lau 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.