Impactor with no spin (VIDEO) Durham University This video is under embargo. Please login to access this video. Caption A cross-section of a 3D simulation run by researchers investigating how a collision between the early-Earth and a Mars-size object might have led to the formation of the Moon. When no spin was added to the impactor (Theia) the collision with the early Earth produced a self-gravitating clump of material with a mass of about 80 per cent of the Moon. Credit Sergio Ruiz-Bonilla 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.