Effects of LHB onto Ganymede and Callisto (image) Southwest Research Institute Share Print E-Mail Caption Interior density structures created by an outer solar system late heavy bombardment onto Ganymede (top row) and Callisto (bottom row). The left column shows the density at the surface as a function of latitude and longitude, and the right column shows a slice through the center of the globe. Colors show the density, with black representing pure rock, blue representing mixed ice and rock, and white showing pure ice. Credit Southwest Research Institute Usage Restrictions Embargoed until 1 p.m. Eastern, Jan. 24, 2010 Share Print E-Mail 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.