After the lunar module of Apollo 14 set down on the Moon, Astronauts Alan Shepard and Edgar Mitchell deployed the Apollo Lunar Surface Experiments Package (ALSEP) and collected samples of lunar material. The ALSEP scientific experiments included a seismometer sensitive to slight lunar surface movements, and charged particle detectors which measured the solar wind. The seismometer successfully measured surface tremors interpreted as moonquakes and meteoroids striking the Moon, while the solar wind experiment was sensitive enough to detect the element argon. These and other ALSEP experiments helped classify the internal structure and magnetic field of Earth's Moon. Shepard and Mitchell also made a geology traverse to the rim of Cone Crater, carrying their tools and sample containers in the Modular Equipment Transporter (MET). In this picture Alan Shepard assembles a core tube which he will then hammer into the surface.