Lobate Scarps on the Moon (IMAGE) NASA/Goddard Space Flight Center Caption Lobate scarps (a type of cliff) on the moon are found mostly in the highlands, and are relatively small and young. Scientists propose that they form as result of fracturing of the crust as the moon shrinks. Why is the moon shrinking? As the core slowly cools portions freeze from a liquid to a solid thus taking up less volume. Since the lobate scarps are small, hundreds of meters to several kilometers in length, and 10 to 50 meters in height, they must be young; otherwise everyday small meteor bombardment would have obliterated them. Credit NASA/Goddard/Arizona State University 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.