MARE CRISIUM IMPACT BASIN (IMAGE) Southwest Research Institute Caption From within the Mare Crisium impact basin, the SwRI-led Lunar Magnetotelluric Sounder (LMS) may provide the first geophysical measurements representative of the bulk of the Moon. Most of the Apollo missions landed in the region of linked maria to the west (left image), whose crust was later shown to be compositionally distinct (right image) as exemplified by the concentration of the element thorium. Mare Crisium provides a smooth landing site on the near side of the Moon outside of this anomalous region. Credit NASA Usage Restrictions No restrictions. License Public Domain 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.