Huge Cave Found under Surface of Moon

Tokyo, Oct. 18 (Jiji Press)--An international research team, including the Japan Aerospace Exploration Agency, or JAXA, said Wednesday that it has found a 50-kilometer-long cave under the surface of the moon through a study of observation data from JAXA's Kaguya (Selene) lunar orbiter launched in 2007. The cave, located under an area called the Marius Hills, could be a candidate site for a future lunar exploration base because temperatures inside are stable and effects of radiation are limited, according to the team. The team's finding was published in U.S. science magazine Geophysical Research Letters. Kaguya collected a massive volume of data by orbiting the moon for one and a half years from 2007. In 2009, it found a hole, which is about 50 meters in both diameter and depth, at the Marius Hills. Members of the team, including Tetsuya Kaku, a graduate student of Tokai University, and Junichi Haruyama, associate professor at JAXA, analyzed data collected by the explorer's Lunar Radar Sounder, and investigated the underground structure around the hole. As a result, the team found a cave stretching some 50 kilometers west from a point several tens of meters to 200 meters deep near the hole. The cave is believed to have a width of several tens of meters. The Ocean of Storms, an area in the western part of the moon including the Marius Hills, is covered with basalt from magma from volcanic activities some 3.5 billion years ago. Like caves found around Mount Fuji in central Japan and the Island of Hawaii, the cave under the moon is highly likely to have been formed after the lava surface became solid following a fall in its temperatures, according to the researchers. "The cave is a scientifically useful place," Kaku said, citing the possibility of minerals produced at the time of the birth of the moon and water remaining inside it. END