It is essential for students to know that Earth and the Moon both revolve and rotate and these motions have effects that can be observed on Earth.
Day
A day is based on the 24 hours it takes Earth to rotate.
Earth rotates on its axis counterclockwise from west to east; as a result, the Sun appears to rise in the east and set in the west.
Year
A year is based on the 365¼ days it takes Earth to revolve around the Sun.
Earth revolves around the Sun in an elliptical orbit.
Lunar Movement
The Moon revolves with Earth around the Sun as the Moon is revolving around Earth. The Moon revolves around Earth in 29½ Earth days.
Similarly to Earth, as the Moon revolves, it is rotating or spinning on its axis. The rotation time for the Moon is a little over 27 Earth days.
Because the Moon rotates and revolves in nearly the same amount of time, the same side of the Moon always faces Earth.
Phases of the Moon
As the position of the Moon changes as it revolves around Earth, the observations of the Moon from Earth are seen as phases (new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent) The cause of the phases of the Moon depends on how much of the sunlit side of the Moon faces Earth.
Eclipses
Eclipses of the Sun and Moon are a result of an alignment of Earth, Sun, and Moon.
A solar eclipse occurs when the Moon is directly in-between the Sun and Earth, blocking the Sun’s light casting a shadow over a certain area on Earth.
A lunar eclipse occurs when Earth is directly in-between the Sun and the Moon, blocking the Sun’s light so that Earth’s shadow hits the Moon casting a shadow over the Moon.
Tides
Tides are changes in the surface levels of Earth’s ocean water caused by the effects of the Moon’s and Sun’s gravity on Earth. The effects of tides are most noticeable along ocean shorelines.
As the Moon orbits Earth, the waters of Earth closest to the Moon bulge outward toward the Moon; this bulge is the high tide. Another high tide occurs on the opposite side of Earth. Low tides occur in the areas between the two high tides.
When the Sun and the Moon are aligned the high tides are higher and the low tides are lower; these are called spring tides. When the Sun and the Moon are at right angles to each other, the high and low tides, there is the least difference in the tidal range at the shore; these tides are called neap tides.
Day
A day is based on the 24 hours it takes Earth to rotate.
Earth rotates on its axis counterclockwise from west to east; as a result, the Sun appears to rise in the east and set in the west.
Year
A year is based on the 365¼ days it takes Earth to revolve around the Sun.
Earth revolves around the Sun in an elliptical orbit.
Lunar Movement
The Moon revolves with Earth around the Sun as the Moon is revolving around Earth. The Moon revolves around Earth in 29½ Earth days.
Similarly to Earth, as the Moon revolves, it is rotating or spinning on its axis. The rotation time for the Moon is a little over 27 Earth days.
Because the Moon rotates and revolves in nearly the same amount of time, the same side of the Moon always faces Earth.
Phases of the Moon
As the position of the Moon changes as it revolves around Earth, the observations of the Moon from Earth are seen as phases (new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent) The cause of the phases of the Moon depends on how much of the sunlit side of the Moon faces Earth.
Eclipses
Eclipses of the Sun and Moon are a result of an alignment of Earth, Sun, and Moon.
A solar eclipse occurs when the Moon is directly in-between the Sun and Earth, blocking the Sun’s light casting a shadow over a certain area on Earth.
A lunar eclipse occurs when Earth is directly in-between the Sun and the Moon, blocking the Sun’s light so that Earth’s shadow hits the Moon casting a shadow over the Moon.
Tides
Tides are changes in the surface levels of Earth’s ocean water caused by the effects of the Moon’s and Sun’s gravity on Earth. The effects of tides are most noticeable along ocean shorelines.
As the Moon orbits Earth, the waters of Earth closest to the Moon bulge outward toward the Moon; this bulge is the high tide. Another high tide occurs on the opposite side of Earth. Low tides occur in the areas between the two high tides.
When the Sun and the Moon are aligned the high tides are higher and the low tides are lower; these are called spring tides. When the Sun and the Moon are at right angles to each other, the high and low tides, there is the least difference in the tidal range at the shore; these tides are called neap tides.