A phenomenon or process that involves multiple steps and repeats itself

An obscuring of the light from a celestial body by the passage of an object between the celestial body and

the observer or between the celestial body and its source of illumination

When the full moon passes into Earth’s shadow,

causing the Moon to appear reddish in color when

the Sun, Earth, and the Moon directly line up;

lasts 1–31⁄2 hours

The shape of the illuminated portion of the Moon

as seen by an observer, usually on Earth

A celestial body that revolves around a planet

A curved path followed by a satellite as it revolves

around an object

The four natural divisions of the year based on

changes in temperature due to varying amounts of

sunlight received (both intensity and number of

daylight hours vary); caused by the tilt of Earth during its revolution

When the Moon passes between Earth and the Sun,

covering all or part of the Sun; occurs when the Sun,

the Moon, and Earth directly line up; lasts for less

than 12 minutes

A star and the

group of planets

and other celestial

bodies that are

held by its

gravitational

attraction and

revolve around it

A celestial body consisting of a mass of gas held

together by its own gravity in which the energy is

generated by nuclear reactions in its interior

The luminous star

around which

Earth and other

planets revolve;

composed mainly

of hydrogen and

helium

The slant of Earth’s

axis, which is 23.5

degrees from

vertical compared to

Earth’s orbital plane

around the Sun;

results in the North

Pole always pointing

toward the North

Star