Parameters Screen (IMAGE) Purdue University Caption The parameters screen of the "Impact: Earth!" website allows users to input the diameter and density of the projectile, the impact angle and velocity, and whether the projectile will hit water or rock. Credit Information Technology at Purdue image/Michele Rund 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.