Scientific Questions in Lunar Exploration*
Major questions in the exploration of the Moon fall chiefly in three
categories of basic problems:
The possibility that ancient rocks and deposits on the Moon's surface
may contain a unique record of events related to the formation or
accretion of the terrestrial planets gives the scientific exploration of
the moon unusual potential significance. There is also the minor
possibility of finding prebiotic material. . . .
- structure and processes of the lunar interior,
- the composition and structure of the surface of the Moon and the
processes modifying the surface, and
- the history or evolutionary sequence of events by which the Moon has
arrived at its present configuration.
The major questions are as follows:
Structure and Processes of the Lunar Interior
- Is the internal structure of the Moon radially symmetrical like the
Earth, and if so, is it differentiated? Specifically, does it have a
core and does it have a crust?
- What is the geometric shape of the Moon? How does the shape depart
from fluid equilibrium? Is there a fundamental difference in morphology
and history between the sub-Earth and averted faces of the Moon?
- What is the present internal energy regime of the Moon?
Specifically, what is the present heat flow at the surface and what are
the sources of this heat? Is the Moon seismically active and is there
active volcanism? Does the Moon have an internally produced magnetic
Composition, Structure, and Processes of the Lunar Surface
- What is the average composition of the rocks at the surface of the
Moon and how does the composition vary from place to place? Are volcanic
rocks present on the surface of the Moon?
- What are the principal processes responsible for the present relief
of the lunar surface?
- What is the present tectonic pattern on the Moon and distribution of
- What are the dominant processes of erosion, transport, and
deposition of material on the lunar surface?
- What volatile substances are present on or near the surface of the
Moon or in a transitory lunar atmosphere?
- Is there evidence of organic or proto-organic materials on or near
the lunar surface? Are living organisms present beneath the surface?
History of the Moon
- What is the age of the Moon? What is the range of age of the
stratigraphic units on the lunar surface and what is the age of the
oldest exposed material? Is a primordial surface exposed?
- What is the history of dynamical interaction between the Earth and
- What is the thermal history of the Moon? What has been the
distribution of tectonic and possible volcanic activity in time?
- What has been the flux of solid objects striking the lunar surface
in the past and how has it varied with time?
- What has been the flux of cosmic radiation and high-energy solar
radiation over the history of the Moon?
- What past magnetic fields may be recorded in the rocks at the Moon's
* Listed here are the "Fifteen
Questions" that formed the basis for subsequent Planning in lunar
exploration. Source: National Academy of Sciences-National Research
Council Publication 1403, Space Research: Directions for the
Future (Washington, 1966), pp. 21-22.