Lunar Day Three
Tonight we will return again to the northeast quadrant of the Moon for a closer look at Mare Crisium region (Fig. 4.1). The “Sea of Crises” is not only unique for its lack of connection with any other maria, but it is home to a gravitational anomaly called a mascon. This “mass concentration” might possibly consist of fragments of the asteroid or comet whose impact with the lunar surface created the basin buried beneath the lava flow. The mascon creates an area of high gravity and causes changes in the orbits of lunar probes. This excess gravity has even been known to cause low orbiting lunar satellites to either crash land or be flung out into space! Take a look at Mare Crisium in your telescope and trace the long frozen wave of lava along its west bank known as Dorsum Oppel. Did you catch the two small punctuations of crater Swift to the north and crater Pierce to its south? When you reach the central point of the western shoreline, look for Promontoriums Olivium and Lavinium. It is easy to catch the sharp, small crater Picard to the east, but did you spot the ruins of crater Yerkes between them? Or, even tinier Curtis east of Picard?