On a clear night when the moon is almost full, it is very easy to identify the region where the ‘Eagle’ landed on July 20th, 1969. The Sea of Tranquility is one of a number of darker features - the lunar maria- visible on the lunar surface. Its color is due to a type of volcanic rock, called basalt, which has formed by the cooling of lava flows that filled the lowlands over 3.8 billion years ago. Unlike Earth, the Moon does not have a large magnetic field or an atmosphere to protect its surface from incoming meteorites and charged particles of the solar wind. Such exposure has led to repeated fracture and melting of the basaltic bedrock resulting in it being covered by a fine charcoal gray powder.
During the Apollo 11 mission, astronauts Neil Armstrong, Buzz Aldrin and Michael Collins brought back over 21 kilograms of rock and soil samples from the lunar surface. These have been the focus of many scientific studies. Surprisingly, only 25% of the lunar soil from the Sea of Tranquility is fragmented basaltic rock: the vast majority of the soil particles (~60%) are agglutinates - agglomerates of tiny mineral and glass fragments encased in a glassy matrix. The remainder is a fascinating collection of particles of all shapes and sizes including tiny glass spheres, teardrops and dumbbells; vesicular glass; microbreccias, and many different types of mineral fragments.
Over the past 40 years, there have been some significant advances in microscopy techniques. At Lehigh, we have exploited both new and well established techniques in scanning electron and X-ray imaging to give you a microscopic view of the lunar surface.
Christopher and Carol Kiely (firstname.lastname@example.org)
Department of Materials Science and Engineering