Moon Phases Quiz Review Guide

Moon Phases

the different shapes of the Moon's illuminated portion as seen from Earth, caused by the changing angles at which sunlight illuminates the Moon as it orbits our planet.

Rotation

the circular movement of an object around a central axis or point, either internal or external to the object.

Revolution

a complete orbital path around a central point or axis

Lunar calendar

a dating system that bases its months on the cycles of the Moon's phases

Moon’s Orbit

a nearly elliptical path, with the Earth at one of the foci, and the Moon completing one orbit (a sidereal month) in approximately 27.3 days.

Solar Eclipse

occurs when the Moon passes between the Sun and Earth, causing the Moon to block all or part of the Sun's light and casting a shadow on Earth, which can be a total, partial, or annular eclipse depending on the Moon's position relative to the Sun and Earth.

Lunar Eclipse

occurs when the Earth passes between the Sun and the Moon, causing Earth's shadow to fall on the Moon, which then appears dimmer and sometimes reddish.

Earth’s Atmosphere

a gaseous envelope surrounding the planet, composed primarily of nitrogen and oxygen, held in place by Earth's gravity, and divided into layers based on temperature and composition.

Umbra

the dark, central, and fully shaded part of a shadow where the light source is completely blocked by an opaque object.

Penumbra

the outer, partially shaded region of a shadow cast by an opaque body, where only a portion of the light source is blocked

Waxing

the moon's phase, where the illuminated area appears to grow larger, from new to full.

Waning

a gradual decrease or decline in size, extent, or intensity.

Gibbous

a phase of the moon (or a planet) where more than half, but not all, of its visible disk is illuminated, appearing as a bulging or rounded shape.

Crescent

the shape of the moon between its first or last quarter and the new moon, characterized by a concave and convex edge terminating in points.

New Moon

the phase of the moon when it is in conjunction with the sun and invisible from earth, or shortly thereafter when it appears as a slender crescent.

Full Moon

occurs when the Moon is on the opposite side of Earth from the Sun, resulting in the entire side facing Earth being fully illuminated by the Sun.

First Quarter Moon

the third phase of the lunar cycle where half of the moon's visible surface is illuminated, occurring roughly a week after the new moon.

Third Quarter Moon

a lunar phase where the Moon appears half-illuminated, occurring roughly three weeks after a new moon, and rising around midnight, setting around noon.

Ray

a narrow beam of light or radiation, or a straight line that extends infinitely in one direction from a point, depending on the context, whether it's physics, optics, or geometry.

Crater

a bowl-shaped depression, or hollowed-out area, produced by the impact of a meteorite, volcanic activity, or an explosion.

Maria

huge basins containing lava flows marked by craters, ridges, faults, and straight and meandering valleys called rilles and are devoid of water.

Meteoriod

space rocks that range in size from dust grains to small asteroids.