Figure-model-features-a-porous-rubble-pile (IMAGE) SETI Institute Caption Our model features a porous rubble pile, made up of a mix of CO and refractory amorphous H2O ice, with specific pore radii 𝑟𝑝. The top layer, depicted in brown, undergoes thermal processing in just one orbit, resulting in the loss of CO (both ice and gas) in this layer. Below the sublimation front 𝑟𝑏, shown in dark blue, the original CO ice volume remains intact. Over time, as the sublimation front progresses downward (to the right in the model), CO ice embedded in the amorphous H2O ice matrix begins to sublimate. The gas produced, indicated in light blue, then fills the pores and moves upward, away from the sublimation front. Credit SETI Institute Usage Restrictions none 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.