Motions of Earth, The Moon and PlanetsSection 7.3

Learning Goals: • I will understand key terms: rotation, revolution, tilt, solstice, eclipse• I will understand how Earth’s tilt affect the season.• I will understand how the Moon affects tides• I will understand how eclipses occur.

Earth’s Motion

•Earth’s Rotation: • Earth spins on its axis = ROTATION• it takes Earth 24 hours to rotate

• Earth’s Revolution:• Earth moves around the Sun = REVOLUTION• it takes Earth 365.25 days to revolve

• Earth’s Tilt:• Earth is tilted 23.5 from the vertical

Gravity

• Gravitation force: the force of attraction between all masses in the Universe• Earth stays in orbit because of the balance between its forward speed and the Sun’s gravitational pull

Seasons

• Solstice: when the tilt is either closest or furthest from the Sun – first day of Summer (closest tilt) first day of Winter (furthest tilt)• Equinox: when the hours of daylight = hours of darkness (first day of Spring & first day of Fall)

Phases of the Moon• The Moon is non-luminous as it reflects the light from the Sun.• We see different amounts of the illuminated surface of the Moon. They follow a predictable pattern called the lunar cycle.

Moon Phases

• New Moon: the Moon is dark, we cannot see• Waxing = getting larger• Waning = getting smaller• Full Moon • Quarter = half Moon

Tides – The Pull of the Moon

• Tide – the rising and falling of the ocean• When the Moon is overhead there is HIGH TIDE• The Moon’s gravity pulls the Earth & water towards it

Eclipses• Eclipse: the darkening of a celestial object due to the position of another celestial object• Lunar Eclipse: Occurs when the Earth is positioned between the Sun and the Moon.•Solar Eclipse: occurs when the Moon is positioned between the Sun and Earth

Today’s Tasks

Pg. 290 #2, 3, 4, 5, 6, 7, 8