Rubble Pile (IMAGE) Southwest Research Institute Caption Prior to the impact of NASA’s Double Asteroid Redirection Test (DART) into the moonlet Didymos, Southwest Research Institute engineers and scientists performed an experiment to study the effects of the impact. Because Dimorphos was thought to be a “rubble pile” asteroid made up of pieces of rock bound together by gravity, the moonlet was represented in the experiment by a collection of rocks and stones, which were placed in a wooden frame before being bonded together by cement. Credit Southwest Research Institute Usage Restrictions Images/Videos may be used by the public for educational and informational purposes only. License Original 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.