Glossary

Apogee- When the moon is the farthest from Earth.

Apollo - U. S. Space Program which included 6 piloted lunar landing between 1969 and 1972.  Apollo astronauts collected and returned 382 kilograms of rock and sediment samples from the Moon.  

Astronaut - A person engaged in or trained for space flight.

Atmosphere - the envelope of gases surrounding the earth and held to it by the force of gravity.

Black holes - An extremely small region of space with a gravitational field so intense that nothing can escape, not even light.

Blue Moon - The second full moon in any month.  It happens about 3 times a year, hence the term "once in a blue moon". 

Centrifugal force - the force that seems to pull an object outward as it moves in a circle.

Centripetal force - the force that is required to keep an object moving around a circular path.

Comet - A relatively small celestial body consisting of a frozen mass that travels around the sun in an elliptical orbit .

Core -  The central part of an object.

Crater - A hole or depression.  Most are shaped like a circle or oval. 

Eagle - The landing craft that the Apollo astronauts used to land on the moon's surface.

Earthquake - Sudden motion or trembling of Earth caused by the abrupt release of slowly accumulated elastic energy in rocks. 

Farside - The side of the Moon that never faces Earth.

Fra Mauro - Landing site name of Apollo 14 on the Moon on February 5, 1971.

Galileo, Galilei - an Italian inventor, astronomer, and physicist who lived from 1564 -- 1642 , famous for making the first working telescope.

Gibbeous moon - the phases of the moon lying between First Quarter and Last Quarter, during which the moon looks lopsided.

Gravity- the pulling attraction experienced near large massive bodies, especially on or near the surface of a planet or a star.

Hadley-Appenine - Landing site name of Apollo 15 on the Moon on  July 31, 1971.

Harvest moon - a name for the full moon nearest the September equinox, which for three or four days around full rises only a little later each night. (Associated with the harvest season at this time.)

Hunter's moon - the full moon in October, which for three or four days around full rises only a little later each night. (Thought of as providing more light for a night hunter.)

Impact - The forceful striking of one body, such as a meteorite, against another body such as a moon or planet.

Lava - Fluid magma that flows on the surface of a planet or moon; erupted from a volcano or fissure.  Also, the rock formed by solidification of this material.   

Luna - the Latin and Spanish word for moon.

Lunar - Anything having to do with the moon. 

Lunar eclipse - When the Moon (or a portion of it) enters the Earth's shadow.

Lunar Roving Vehicle - The Apollo lunar roving vehicle was a “moon buggy”.  It was battery powered and held two astronauts.  The wheels were made of wire mesh and it traveled easily over the rocks on the moon’s surface.   It could carry twice it’s own weight.   The rover folded up inside the lunar lander during trip to the moon.   

Magma - Molten rock in the inside of the planet or moon. 

Maria - Dark areas on the Moon covered by lava flows.

Meteorite - A metallic or stony body that has fallen on Earth or the Moon from outer space.

Moonquake - Sudden motion or trembling of the Moon caused by the release of energy in rocks.

Nearside - The side of the Moon that always faces the Earth.

Ocean of Storms - Landing site name of Apollo 12 on the Moon on November 19, 1969. 

Orange Moon - similar to a blue moon but it is the third full moon in any one season of the year.  

Orbit - the path followed by celestial objects moving under gravity, such as the path of the moon around the earth or the path of a spacecraft or artificial body around a celestial body (e.g., a communications satellite around the earth)

Perigee - When the moon is closest to Earth.

Phases - The name we give to the different views of the moon.  The technical version: the apparent changes in the size and shape of the moon caused by the differing amounts of sunlight reflected by the moon toward the earth during the moon's orbit; the eight phases are the new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, and waning crescent.

Regolith - Loose rock, mineral or glass fragments.  On the Moon, this debris covers the surface.  

Revolution - to spin.  

Revolve - To go around another object.

Rille - a long, narrow, trenchning.  The orbiting of one heavenly body around another.-like valley on the surface of the moon; it may be straight or winding.

Rotation -  the movement of a body in relation to an internal point. One thing moving around another.

Sea of Serenity - The landing site of Apollo 11, 1969.

Solar System - The Sun and all the objects (planets, moons, asteroids and comets) that orbit the Sun.

Spacecraft - Vehicle capable of traveling in outer space.

Taurus-Littrow - Landing site name of Apollo 17 on the Moon on December 11, 1972.

Tides - slow-moving water waves with long wavelengths. They produce an alternate rise and fall in the surface level of the oceans. When the tide comes in, the water level rises and the tides break further and further inland. At the point when the surface level of the ocean is at its highest point, it is high tide. Once the high point has been reached, the tides begin to subside. When the water surface level reaches its lowest point it is low tide. The only celestial bodies close enough to the earth to exert a gravitational force on it are the sun and the moon. 

Waning Moon - the lunar phases from the new moon through the full moon.

Waxing Moon - lunar phases that occur after the full moon but before the new moon; so-called because its illuminating area is decreasing.