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Glossary:
Astronomical Units: the distance between Earth and Sun
A quarter million miles: more accurately, and in more appropriate units for science, but perhaps less memorably: 385,000 km, although the eccentric orbit of the Moon brings it as close as 363,300 km and takes it as far away as 405,500 km.
Basins: the remnants of the largest craters, often showing concentric structures. The two major basins on the Moon are Orientale and Imbrium.
Center of Attraction: two bodies in space, like the Earth and the Moon, don't in fact "orbit each other". Each orbits a central point defined by the ratio of thie masses. This unmarked mathematical center is known as the Center of Attraction.
Chromosphere: the transition region between the Sun’s relatively cool photosphere, and the hot corona.
Corona: the outermost region of the solar atmosphere, consisting of ionized gas at temperatures of several million degrees Kelvin.
Crater: circular depression excavated by the impact of a meteor or asteroid, often surrounded by a ring of ejected debris.
Conduction: heat transfer through materials such as a bowl, cup or wall.
Convection: heat transfer through openings such as cracks, gaps or where pockets of heated air can escape and become cooled.
Earth’s axis: an imaginary vertical line that cuts directly through the center of Earth and earth spins around this line. The axis is tilted at an angle of 23.5°.
Ellipse: an elongated closed curve.
Equinox: occurs when the Sun is directly above Earth's equator, equal amounts of daylight and night, marks the beginning of fall or spring.
Galileo: a scientist in the early 1600’s who first pointed a telescope skyward. He discovered sunspots, craters on the moon, and the four largest satellites of Jupiter.
Hans Bethe: (1906- ) a theoretical physicist who postulated nuclear fusion of Hydrogen to Helium as a power source for the Sun.
Hydrostatic Equilibrium: the balancing process that prevents the Sun from exploding
Kelvin: temperature scale
Mares: the dark, smooth(er) plains of the Moon, known as 'seas' since the seventeenth century, but in fact containing no water.
Mass: a measure of the quantity of matter in a body.
Nuclear fusion: a thermonuclear reaction in which nuclei fuse together to form a more massive nucleus. Since the resulting nucleus is less massive that the sum of the initial nuclei, energy is released.
Phase: one of the successive stages of illumination of the Moon. The eight phases are, in order: new, waxing crescent, first quarter, waxing gibbous, full, waning gibbous, third quarter, waning crescent.
Photosphere: the bright, thin layer of the Sun’s atmosphere from which we receive the most visible radiation.
Photons: light particles that are emitted from the sun
Revolution: Earth's yearly orbit around the Sun.
Rotation: the spinning of Earth on its axis, the reason for day and night.
Sea of Tranquillity: Mare Tranquillitatis, where the Apollo 11 astronauts landed. It is the dark 'sea' at about the "two-thirty" position on the Moon's surface, about half way between the center and the edge.
Seven thousand miles around: all right, already: its diameter is 3,500 km and its circumference is 3,500 km times pi (3.1415926....).
Solar system: our sun, and the nine planets, their satellites, asteroids, comets and other minor bodies that orbit the Sun.
Solstices: day when Sun reaches its greatest distance north or south of the equator; marks the beginning of winter or summer.
Twenty-nine days (point five three): the Moon's orbital period around the Earth is 27.32 days - one lunar month. The Moon is locked in phase with the Earth ("synchronous rotation"), so its period of rotation around its own axis is also 27.32 days and it keeps the same face turned towards the Earth. However, the time between successive new Moons is a little different - 29.53 days, due to the distance moved by the Earth around the Sun during this time.
Uplands: heavily-cratered, and rougher and brighter in appearance, the uplands are the more mountainous areas that cover most of the Moon's surface.
Wane: the Moon 'waxes' in the first half of its cycle, when the illuminated surface visible from Earth is increasing, and 'wanes' in the second half, when the illuminated surface we see is decreasing
Astronomical Units: the distance between Earth and Sun
A quarter million miles: more accurately, and in more appropriate units for science, but perhaps less memorably: 385,000 km, although the eccentric orbit of the Moon brings it as close as 363,300 km and takes it as far away as 405,500 km.
Basins: the remnants of the largest craters, often showing concentric structures. The two major basins on the Moon are Orientale and Imbrium.
Center of Attraction: two bodies in space, like the Earth and the Moon, don't in fact "orbit each other". Each orbits a central point defined by the ratio of thie masses. This unmarked mathematical center is known as the Center of Attraction.
Chromosphere: the transition region between the Sun’s relatively cool photosphere, and the hot corona.
Corona: the outermost region of the solar atmosphere, consisting of ionized gas at temperatures of several million degrees Kelvin.
Crater: circular depression excavated by the impact of a meteor or asteroid, often surrounded by a ring of ejected debris.
Conduction: heat transfer through materials such as a bowl, cup or wall.
Convection: heat transfer through openings such as cracks, gaps or where pockets of heated air can escape and become cooled.
Earth’s axis: an imaginary vertical line that cuts directly through the center of Earth and earth spins around this line. The axis is tilted at an angle of 23.5°.
Ellipse: an elongated closed curve.
Equinox: occurs when the Sun is directly above Earth's equator, equal amounts of daylight and night, marks the beginning of fall or spring.
Galileo: a scientist in the early 1600’s who first pointed a telescope skyward. He discovered sunspots, craters on the moon, and the four largest satellites of Jupiter.
Hans Bethe: (1906- ) a theoretical physicist who postulated nuclear fusion of Hydrogen to Helium as a power source for the Sun.
Hydrostatic Equilibrium: the balancing process that prevents the Sun from exploding
Kelvin: temperature scale
Mares: the dark, smooth(er) plains of the Moon, known as 'seas' since the seventeenth century, but in fact containing no water.
Mass: a measure of the quantity of matter in a body.
Nuclear fusion: a thermonuclear reaction in which nuclei fuse together to form a more massive nucleus. Since the resulting nucleus is less massive that the sum of the initial nuclei, energy is released.
Phase: one of the successive stages of illumination of the Moon. The eight phases are, in order: new, waxing crescent, first quarter, waxing gibbous, full, waning gibbous, third quarter, waning crescent.
Photosphere: the bright, thin layer of the Sun’s atmosphere from which we receive the most visible radiation.
Photons: light particles that are emitted from the sun
Revolution: Earth's yearly orbit around the Sun.
Rotation: the spinning of Earth on its axis, the reason for day and night.
Sea of Tranquillity: Mare Tranquillitatis, where the Apollo 11 astronauts landed. It is the dark 'sea' at about the "two-thirty" position on the Moon's surface, about half way between the center and the edge.
Seven thousand miles around: all right, already: its diameter is 3,500 km and its circumference is 3,500 km times pi (3.1415926....).
Solar system: our sun, and the nine planets, their satellites, asteroids, comets and other minor bodies that orbit the Sun.
Solstices: day when Sun reaches its greatest distance north or south of the equator; marks the beginning of winter or summer.
Twenty-nine days (point five three): the Moon's orbital period around the Earth is 27.32 days - one lunar month. The Moon is locked in phase with the Earth ("synchronous rotation"), so its period of rotation around its own axis is also 27.32 days and it keeps the same face turned towards the Earth. However, the time between successive new Moons is a little different - 29.53 days, due to the distance moved by the Earth around the Sun during this time.
Uplands: heavily-cratered, and rougher and brighter in appearance, the uplands are the more mountainous areas that cover most of the Moon's surface.
Wane: the Moon 'waxes' in the first half of its cycle, when the illuminated surface visible from Earth is increasing, and 'wanes' in the second half, when the illuminated surface we see is decreasing