aa -- A basaltic lava with a rough, jagged surface.
achondrite -- A stony meteorite, coarsely crystallized, with sizable fragments of various minerals visible to the naked eye.
Adams -- John Couch Adams (1819-1892) English astronomer. One of the discoverers of the planet Neptune.
Akna -- In Native American traditions from Mexico and from the Arctic, "Moon" (Wife of the Sun) and "The Mother" (Goddess of Childbirth), respectively.
albedo -- The ratio of the amount of solar radiation reflected from an object to the total amount incident upon it.
Alcott -- Louisa May Alcott (1832-1888) American author.
altimetry -- The measurement of elevation or altitude.
anorthosite -- A type of igneous rock composed almost entirely of feldspar, a group of minerals that make up about 60% of the Earth's crust.
antipodal point -- The opposite point with respect to any given point.
Aphrodite -- One of the twelve Greek Olympian gods. Goddess of Love (Roman name, Venus), daughter of Zeus and Dione .
Apollo -- In Greek mythology, one of the twelve Olympian gods. God of prophecy, healing, archery, music, youth, plastic arts, science and philosophy.
arachnoid -- Spider or cobweblike feature on the surface of Venus, typically having a diameter of about 100-km and a central volcanic structure surrounded by a complex network of lineaments.
arcuate -- Curved or bent.
Ariel -- In Alexander Pope's poem "The Rape of the Lock", a spirit of the air, chief of the sylphs.
asteroid -- One of many small rocky bodies orbiting the Sun; a concentration of these bodies makes up the Asteroid Belt between Mars and Jupiter.
Atla -- In Norse mythology, a giantess, mother of Heimdall.
Atlas -- In Greek mythology, brother of Prometheus and grandfather of Hermes (Mercury). Condemned to stand forever supporting the heavens on his shoulders. The Atlantic Ocean is named for him.
Ba'het -- In Egyptian mythology, goddess of wealth and abundance.
Balch -- Emily Balch (1867-1961) American economist, Nobel Laureate.
Barton -- Clara Barton (1821-1912) Founder of American Red Cross.
basalt -- Fine-grained igneous rock (rich in mafic minerals) that has erupted onto the surface.
basin -- A depressed area with no surface outlet.
bedrock -- Continuous solid rock that underlies regolith and is exposed at outcrops.
breccia -- Coarse-grained rock composed of angular fragments of pre-existing rock.
caldera -- A large volcanic depression at the summit of a volcano, caused by collapse or explosion.
Callisto -- In Greek mythology, a nymph, follower of Artemis. Zeus wanted to woo her, and so disguised himself as Artemis and seduced her. To hide her from his jealous wife Hera, Zeus changed Callisto into a bear.
Candor -- Candor Chasma - from the Latin candor, meaning "blaze" or "the white" from its appearance.
Carson -- Rachel Carson (1907-1964) American biologist and author.
Cassini -- Gian Domenico Cassini (1625-1712) Astronomer born in Italy, later a naturalized French citizen. Discovered four of Saturn's satellites, observed a dark division in Saturn's ring (the Cassini Division).
Centaur -- In Greek mythology, a being with the head, arms, and torso of a man, and the body and legs of a horse. The personification of wisdom and beastliness: the two natures of humankind.
Cerberus -- In Greek mythology, the three-headed dog that guards the entrance to the underworld.
Charon -- In Greek mythology, ferryman of the River Styx, who carried the dead to the underworld. Each dead person was buried with a coin in his mouth or on his eyelids to pay for the crossing.
chasma -- A large canyon.
chondrite -- A stony meteorite, composed of finely crystallized material.
coma -- A roughly spherical region of diffuse gas which surrounds the nucleus of a comet. Together, the coma and the nucleus form the comet's head.
comet -- A small celestial body composed at least partially of ices. Comets either orbit the Sun or pass through the Solar System on hyperbolic orbital paths .
Cordelia -- In William Shakespeare's King Lear, the youngest daughter of the king.
corona -- A circular to elongate feature which is surrounded by multiple concentric ridges. Coronae are thought to be formed by hot spots.
crater -- An approximately circular depression, sometimes surrounded by a raised rim. Craters are typically formed by explosion during meteorite impact.
crust -- The outermost layer of the lithosphere.
cuspate -- Shaped like a cusp; a sharp projection of material.
Dactyl -- In Greek mythology, a legendary being that lived on Mount Ida.
Danu -- The greatest of the goddesses of ancient Ireland.
Deimos -- In Greek mythology, a son of Ares (Mars) who, with brother Phobos, was a constant companion to his father.
Derceto -- Philistine fertility goddess.
Dione -- In Greek mythology, the mother of Aphrodite, and daughter of Zeus.
drift -- A general term for all rock debris transported from one place and deposited in another, and distinguished from solid bedrock.
Eistla -- In Norse mythology, a giantess.
ejecta -- Material thrown out of a volcano or impact crater.
Enceladus -- In Greek and Roman mythology, a giant, son of Titan and Gaea. Buried by an angry Zeus under Mount Etna. When the giant hisses and thrusts out his fiery tongue, Mount Etna erupts.
Encke -- Johann Franz Encke (1791-1865) German astronomer at the Seeberg Observatory, Switzerland. Determined period of the comet discovered by Pons and showed it to be identical with comets of other years.
escarpment -- A long, more or less continuous cliff or relatively steep slope facing in one general direction, produced by erosion or faulting.
Europa -- In Greek mythology, a mistress of Zeus to whom he appeared as a gentle white heifer. Zeus persuaded her to take a ride on his back, and then he carried her away across the sea.
fault -- A fracture or zone of fractures in a planet's crust, accompanied by displacement of the opposing sides.
feldspar -- A group of rock-forming minerals that make up about 60% of the Earth's crust.
Fortuna -- In Roman mythology, goddess of fortune, chance and luck.
Galileo -- Galileo Galilei (1564-1642) Italian mathematician, astronomer, and physicist. First to use a telescope to observe the skies.
Galle -- Johann Gottfried Galle (1812-1910) German astronomer who discovered the crepe ring of Saturn (1838) and was a co-discoverer of Neptune (1846).
Ganymede -- In Greek mythology, a beautiful Trojan boy, son of Tros and Calirrhoe. Befriended by Zeus and made cupbearer to the Olympian gods.
Gaspra -- Russian resort and spa near Yalta, Crimea, where Leo Tolstoy was treated.
geomorphology -- The study of the external structure, form, and arrangement of rocks in relation to the development of landforms.
geyser -- A type of hot spring that intermittently erupts jets of material.
Giotto -- Giotto di Bondone (1267?-1337) Italian medieval painter, architect, and sculptor.
graben -- A long, relatively depressed crustal unit or block that is bounded by faults along its sides; a trough.
Gula -- One of the primary goddesses of the Akkadian and Babylonian peoples. The mother-goddess and great physician, she had the power to inflict as well as cure disease.
Hadley -- John Hadley (1682-1744) English mathematician and inventor. Built first serviceable reflecting telescope and invented an improved quadrant known as Hadley's quadrant.
Halley -- Edmond Halley (1656-1742) English astronomer. In 1758, predicted accurately the return of a comet previously observed in 1531, 1607, 1682. The body was subsequently named Halley's Comet.
Hellas -- The Greek name for Greece.
Herschel -- Sir William Herschel (1738-1822). British astronomer. Built reflecting telescope of superior quality and with it discovered planet Uranus . Discovered satellites of Uranus and of Saturn.
Hestia -- In Greek mythology, one of the twelve Olympian gods. Sister of Zeus and goddess of the hearth and home (Roman name, Vesta).
Hubble -- Edwin Powell Hubble (1889-1953) American astronomer known for seminal work in modern cosmology.
hummocky -- Uneven; describing a terrain abounding in irregular knolls, mounds, or other small elevations.
Humorum -- Mare Humorum - Latin for "Sea of Humors" or "Sea of Moisture".
Hyperion -- In Greek mythology, a Titan, son of Uranus and Gaea. Husband of Theia and father of Eos (the Dawn). A handsome wanderer, his name is said to signify height or superiority.
Iapetus -- In Greek mythology, a son of Uranus and Gaea. Father of Atlas, Epimetheus, Menoetius, and Prometheus.
Ida -- In Greek mythology, the mountain on Crete where Zeus spent his childhood.
igneous rock -- Rock solidified from a molten state.
Imbrium -- Mare Imbrium - Latin for "Sea of Rains".
Inverness -- In William Shakespeare's Macbeth, the location in Scotland of Macbeth's castle.
Io -- In Greek mythology, a young woman seduced by Zeus, who then transformed her into a heifer to protect her from his jealous wife.
Ishtar -- In Babylonian mythology, goddess of love and war. Ruler of the Moon, as well as the morning and evening stars (alternate names for the planet Venus).
Ithaca -- A Greek island, home of Odysseus.
Jovian -- Of or relating to the planet Jupiter.
Jupiter -- Planet fifth in order from the sun. In Roman mythology, ruler of the gods. (Greek name, Zeus).
Kennedy -- John F. Kennedy (1917-1963) 35th president of the United States. Called on NASA to put an astronaut on the moon within the decade of the 1960's, a feat that was achieved. Died by assassination in November, 1963.
Kuiper -- Gerard Peter Kuiper (1905-1973) American astronomer born in The Netherlands. Studied the origin of the solar system, and planetary atmospheres.
Lada -- A word meaning both "woman" and "goddess" in the area of Lycia in Asia Minor.
Lakshmi -- In Indian mythology, the goddess of all forms of wealth. The reverence for cows in Hindu India is based on worship of this goddess, as in that tradition cows are a representation of wealth.
Lavinia -- In Virgil's Aeneid, a beautiful woman who became the wife of Aeneus. Personification of earth's fertility.
Lee -- Robert E. Lee (1807-1870) American Soldier. General in chief of all Confederate armies during the Civil War. Surrendered to Federal forces in April, 1865.
Leverrier -- Urbain Jean Joseph Le Verrier (1811-1877) French astronomer who performed the calculations that predicted the existence of the planet Neptune.
limb -- The outer edge of a lunar or planetary disk.
Lincoln -- Abraham Lincoln (1809-1865) Sixteenth president of the United States. Commander in Chief of Federal forces during the Civil War. Five days after the war's end Lincoln was shot. He died the following day.
lineament -- A linear topographic feature, such as a fault line, aligned volcanoes, or straight stream course.
Loki -- In Scandinavian mythology, a mischievous trickster, thief and slanderer.
Magellan -- Ferdinand Magellan (1480-1521) Portuguese navigator whose ship completed the first circumnavigation of the Earth.
magma -- Molten rock material (liquids and gases).
magnetosphere -- a region of a planet's atmosphere that is dominated by the planet's magnetic field so that charged particles are trapped in it.
mantle -- The main bulk of a planet between the crust and the core; on Earth, the mantle ranges from about 40 to 2,900 kilometers (25 to 1800 miles) below the surface.
mare -- A dark, low-lying lunar plain, filled to some depth with volcanic rocks.
Mars -- Planet fourth in order from the sun. In Roman mythology, god of war and discord (Greek name, Ares).
massif -- A massive topographical feature, commonly formed of rocks more rigid than those of its surroundings.
Mead -- Margaret Mead (1901-1978) American anthropologist, author and lecturer on contemporary social issues.
Mercury -- The planet closest to the sun. In Roman mythology, the fleet-footed messenger god and escort of dead souls to the underworld (Greek name, Hermes).
meteorite -- A stony or metallic object from interplanetary space that impacts a planetary surface.
Mimas -- In Greek mythology, a giant.
Miranda -- In William Shakespeare's The Tempest, the second daughter of Prospero the magician.
morphology -- The study of structure or form.
Mylitta -- In ancient Phoenicia, a moon goddess who presided over fertility and childbirth.
Navka -- Arab mother-goddess.
Neptune -- Planet eighth in order from the sun. In Roman mythology, god of the sea (Greek name, Poseidon).
nucleus -- The frozen core of a comet which contains almost the entire cometary mass and is located in the comet's head.
Oberon -- In William Shakespeare's A Midsummer Night's Dream, the king of the fairies.
Olympus -- In Greek mythology, the mountain that is home to the gods.
Onatah -- In the mythology of the Native American Seneca and Iroquois people, a corn or wheat goddess; the daughter of Nokomis.
Ophelia -- In William Shakespeare's Hamlet, the daughter of Polonius and deserted lover of Hamlet.
Ophir -- In the Bible, a land to which King Solomon sent a naval expedition. Considered to be the eastern extremity of the know world. Thought to be modern Ethiopia, or possibly India.
Orientale -- Latin for "Eastern".
Ovda -- In Finnish mythology, a wild, ill-humored spirit who wanders through the forests looking for trespassers to tickle to death.
Oxia -- Oxia Palus - from the Latin, an oasis on the Oxus Canal, which flowed into the Oxianus Lacus (the modern-day Sea of Aral).
pahoehoe -- A basaltic lava with a smooth, undulating surface.
perihelion -- The point in the path of a planet, asteroid, comet, or other body that is closest to the sun.
Proteus -- In Greek mythology, the son of Poseidon. Personification of the shifting winds and moods of the sea.
Phobos -- In Greek mythology, a son of Ares (Mars) who, with brother Deimos, was a constant companion to his father.
plateau -- Any comparatively flat area of great extent or elevation.
plume -- A buoyant mass of hot, partially molten mantle material that rises to the base of the lithosphere.
Pluto -- Planet ninth in order, and farthest, from the sun. In Greek mythology, god of the dead and the underworld.
Procellarum -- Oceanus Procellarum - from the Latin "Ocean of Storms".
Prometheus -- A Greek mythological hero who gave humankind fire.
regolith -- Any solid material lying on top of bedrock, including soil and rock fragments.
relief -- The maximum regional difference in elevation.
Rhea -- In Greek mythology, mother of Zeus and wife of Cronos the Titan .
rift -- A valley formed at a divergence zone or other area of extension.
rille -- One of several trenchlike, or cracklike valleys up to several hundred km long and 1-2 km wide commonly occurring on the Moon's surface.
Sacajawea -- Sacajawea (Bird Woman) (1786?-1812) Native American who accompanied and guided the Lewis and Clark expedition from the Missouri River to the Pacific Ocean and back.
Sapas -- In Phoenician mythology, goddess of commerce and travel, and messenger of the gods.
Saturn -- Planet sixth in order from the sun. In Roman mythology, god of agriculture, and father of Jupiter (Greek name, Cronos).
scarp -- A cliff or steep slope of some extent that may form a marked topographic boundary.
Schiaparelli -- Giovanni Virginio Schiaparelli (1835-1910). Italian astronomer at the Milan Observatory who reported markings on Mars which he called "canali".
Selu -- Cherokee corn goddess.
shearing -- The motion resulting from stresses that cause or tend to cause contiguous parts of a body to slide relatively to each other.
shield volcano -- A broad volcanic cone with gentle slopes constructed of successive nonviscous, mostly basaltic, lava flows.
Sif -- In Scandinavian mythology, the grain goddess renowned for her long golden hair. Mate of the thunder god Thor.
SIR-C/X-SAR -- Spaceborne Imaging Radar-C and X- Band Synthetic Aperture Radar. An instrument that performs detailed observations of Earth at any time, regardless of weather or sunlight conditions.
slumping -- A landslide that results from the downward sliding of rock debris as a single mass, usually with a backward rotation relative to the slope along which the movement takes place.
Stickney -- Angeline Stickney (1830-1892) The wife of Asaph Hall, known for her persistent encouragement of her husband as he strove to and eventually succeeded in the discovery of the satellites of Mars.
stratosphere -- An upper portion of a planetary atmosphere, above the troposphere and below the ionosphere, characterized by relatively uniform temperature and horizontal winds.
tectonic -- Relating to the deformation of the crust of a moon or planet, the forces involved in or producing such deformation, and the resulting forms.
tectonics -- Structural deformation, especially folding and faulting.
terminator -- The line separating the illuminated and unilluminated parts of a celestial body; the dividing line between day and night as observed from a distance.
terrestrial -- Belonging to the class of planets that are similar to the Earth in density and composition (i.e. Mercury, Venus, and Mars).
Tethys -- In Greek mythology, a sea goddess.
Tharsis -- In the Bible, a land at the western extremity of the known world. Thought to be a region in modern-day Spain.
Theia -- Pre-Hellenic goddess of light, mother of the dawn. In Greek mythology, mother of Helios (the Sun) and Eos (the Dawn).
Titan -- In Greek mythology, Titans were the firstborn children of Uranus (the sky) and Gaea (the Earth). The ruler of the Titans was Cronos, whose Roman name is Saturn.
Titania -- In William Shakespeare's A Midsummer Night's Dream, the queen of the fairies.
topography -- The shape and form of the surface of a planet.
Triton -- In Greek mythology, merman, half-man, half-fish. Son of Poseidon and Amphitrite.
trough -- A long linear depression.
Umbriel -- In Alexander Pope's poem "The Rape of the Lock", a "dusky, melancholy sprite".
Uranus -- Planet seventh in order from the sun. In Greek mythology, god of the sky, mate of the goddess of the Earth, and father of the Titans.
Ursula -- In William Shakespeare's Much Ado About Nothing, the attendant to Hero.
Valhalla -- In Norse mythology, Odin's hall, where he received the souls of slain warriors.
Venus -- Planet second in order from the sun. In Roman mythology, goddess of love (Greek name, Aphrodite).
vent -- An opening or fissure in a planet's surface through which volcanic material erupts.
Vires-akka -- In Northern European / Arctic mythology, a forest goddess.
viscosity -- A measure of resistance to flow.
volcanic rock -- Rock formed by eruption onto a planet's surface.
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