A quest for the moon

There has been a renewed interest in exploration of the moon in the past few years and a number of space missions are planned by various countries during this decade. The Indian Space Research Organization has also been discussing the possibility of an orbiter mission to the moon for remote sensing and has debated the scientific goals for such a mission in various fora such as the annual meeting of the Indian Academy of Sciences held at Lucknow. The main motivation for the future missions is to resolve some of the problems regarding the formation and early stages of chemical evolution of the moon, which can be clearly defined now in view of the vast database on chemical, geological and chronological aspects that has become available as a result of thirty years of serious study of the samples of the moon and several orbiter missions. An attempt is made here to summarize the salient features of our current understanding of the moon so that scientific objectives of the future missions can be clearly formulated. Specifically, the desirability of a low altitude (100 km) lunar polar orbiter for simultaneous chemical, mineralogic and photogeologic mapping is discussed and some regions on the far side of the moon and polar regions are identified for a detailed study.