APPENDIX F - GLOSSARY
Anorthosite: A granular, textured igneous rock regarded as having solidified at considerable depth. It is composed almost entirely of a soda-lime feldspar.
Apocynthion: The point in the orbit of a moon satellite which is
farthest from the moon.
Apolune: See apocynthion.
Bow shock: The shock wave produced by the interaction of the solar
wind with the earth's dipole magnetic field. It is
also the outer boundary of the magnetosheath (transition region).
Breccia: A course-grained rock composed of angular fragments
of pre-existing rocks in a fine-grained matrix.
Caldera: A broad crater-like basin surrounding a volcanic vent
and having a diameter many times that of the vent.
Circadian rhythm: Relating to biological variations with a cycle of
about 24 hours.
Cislunar: Pertaining to the space between the earth and moon.
Clast: A fragment of rock or mineral, commonly included in a larger rock.
Comprehensive sample: A 1-kilogram collection of rocks representative of a
given area. Desired sample diameters range from approximately 3/8 inch to 1
Contingency sample: Approximately 2 kilograms of lunar material collected
in the immediate vicinity of the lunar module during
the early part of the first extravehicular period.
This is done to increase the probability of returning
a lunar sample to earth if early termination of extravehicular operations is
Densitometric: Relating to determining the degree of opacity of any
Diamagnetic cavity: An area having a magnetic permeability less than one.
Diurnal: Recurring daily. On earth, diurnal processes repeat
themselves every 24 hours; on the moon, every 28 days.
Documented sample: A sample that is photographed before being picked up, the
area photographed after sample removal, and a reference
photograph taken to identify the location.
Double core tube sample: A sample obtained using two drive core tubes connected
end to end.
Earthshine: Illumination of the moon's surface by sunlight reflected from the
earth's surface and atmosphere.
Ecliptic: The plane defined by the earth's orbit about the sun.
Ergometry test: A test performed to measure muscular fatigue under controlled
Front: The outer slopes of a mountain range that rises above
a plain or plateau.
Geomagnetic tail: An elongation of the earth's magnetic field whereby
it is drawn in the anti-solar direction to an undetermined distance. It is also
called the nagnetotail.
Gnomon: A rod mounted on a tripod in such a way that it is
free to swing in any direction and indicate the local vertical.
Hummocky: Multiple low, rounded hills or knolls.
J-missions: A classification of Apollo lunar exploration missions
for which provisions are made for extended lunar surface stay time,
surface vehicular mobility and communications, and more extensive
science data acquisition.
Kilocalorie: An amount of food having an energy-producing value
of one large calorie (equivalent to 1000 gram calories).
Limb: The outer edge of the apparent disc of a celestial
body, as the moon or earth, or a portion of the edge.
Lunar libration: A point in space which, from the viewpoint of an observer
on earth, is about 60 degrees from the
earth-moon axis in the direction of the moon's travel
and on its orbital path.
Lunation: The average period of revolution of the moon about the earth with
respect to the sun. A period of 29 days 12 hours 44 minutes 2.8 seconds. Also
called a synodical month.
Magnetosheath: The region between the solar wind bow shock and the earth's
dipole magnetic field. It varies in size and, within the region, the solar
wind is reduced and the magnetic field is poorly defined. It is also called
the transition region.
Magnetosphere: The region of the earth's atmosphere where ionized gases
contribute to the dynamics of the atmosphere and where the forces of the
earth's magnetic field are predominant.
Magnetospheric plasma: Plasma evolved in the magnetosphere.
Magnetotail: See geomagnetic tail.
Magnetopause: The boundary between the magnetosheath (transition region) and
the earth's dipole magnetic field.
Mare: A large, dark, flat area on the lunar surface (lunar sea).
Mascons: Large mass concentrations beneath the lunar surface. They are
believed to be large bodies that have impacted the lunar surface.
Meru: Milli earth rate unit. One thousandth of the earth's rotational rate.
Metric photography: Photography having an appropriate network of
coordinates or reference points to permit accurate
Monoscopic photograph: A single photograph of a given area, or subject
obtained with a camera having one lens system and shutter.
Morphological: Relating to the shapes and contours of objects or areas.
Moulton Point: A theoretical point on the sun-earth axis thought to be located
about 940 000 statute miles from the earth in the anti-solar direction. It is
also designated as the Ll libration point of the earth.
Noble gases: Monatomic gases that are relatively inert.
Olivine: An igneous mineral that consists of a silicate of magnesium and iron.
Pericynthion: The point in the orbit of a moon satellite that is nearest to
the moon, or the point in the trajectory of a vehicle that is nearest to the
Perilune: See pericynthion.
Phenocrysts: Crystals in igneous rocks that are larger than the crystalline
matrix in which they are imbedded.
Plasma: An electrically conductive gas comurised of neutral particles, ionized
particles, and free electrons, but which as a whole, is electrically neutral.
Plasma sheet: As used in this report, the term refers to a region in the
center of the geomagnetic tail, approximately 10 earth radii in width, in
which there is a marked increase in particle flux.
Porphyritic: The texture of rocks which contain distinct crystals imbedded in
a relatively fine-grained groundmass.
Pyroclastic rocks: Rocks formed by fragmentation as a result of volcanic
Pyroxene: A mineral occurring in short, thick, prismatic crystals, or in
crystals of square cross section; often laminated, and varying in color from
white to dark green or black (rarely blue).
Radial sample: A sample consisting of material taken from a crater's ejecta
field at a crater's rim, at a distance equal to the crater's radius, and at a
distance equal to the crater's diameter.
Radon: A radioactive gaseous element with atomic number 86
and atomic masses of 220 and 222. Formed by the radioactive decay of radium.
Regolith: The surface layer of unsorted fragmented material on the earth or
moon that overlies solid material
Rille: A long, narrow valley on the moon's surface.
Scoriaceous: Having the characteristics of rough, vesicular, cindery, usually
Selenodetic: Relating to the branch of applied mathematics that determines by
observation and measurement the positions of points on the moon's surface and
the size and shape of the moon.
Selenological: Relating to the branch of astronomy that deals with the moon.
Slikensides: Smooth, grooved and polished surfaces of rocks produced by
friction on fault planes and joint faces.
Solar corona: The outer visible envelope of the sun.
Solar wind: Streams of particles (plasma) emanating from and flowing
approximately radially outward from the sun.
Spectrometric: Relating to the measurement of wavelengths of rays of a
Stereoscopic photographs: Two photographs obtained of a given area or subject
from different angles so that the images, when viewed through a stereoscope,
appear as a three-dimensional reproduction of the area or subject
Talus: An accumulated mass of angular rock debris on a hill side or at the
foot of a mountain.
Terminator: The border between the illuminated and dark portions of the moon
Transition region: See magnetosheath.
Umbra: The darkest portion of the shadow of a large body such as the earth or
moon wherein light is completely blocked.
Vesicular: Containing small spherical cavities.
Zodiac: An imaginary belt that extends 8 degrees on either side of the
ecliptic. It includes the paths of the moon and principal planets.
Zodiacal light: A faint glow seen along the zodiac in the west after
sunset and in the east before sunrise.