Period of ROTATION – the amount of time it takes an object to make one complete circle on its axis (Earth rotates from West to East in 24 hours). The rotation of the Earth causes day and night. Period of REVOLUTION – the amount of time it takes an object to travel completely around the Sun (Earth travels counterclockwise around the Sun and its period of REVOLUTION is 365 days) How old are you? How many times have you revolved around the Sun!!

Because the surface of the Earth is curved, the poles receive less energy from the Sun as its beam of light is spread out over more surface area

The Earth experiences seasons due to the 23.5˚ tilt of its axis and it’s motion around the sun. Earth’s elliptical orbit brings it closer to the Sun in the Winter than in the Summer! December Solstice (21 st or 22 nd ) – Earth tilted away from the Sun; in the Northern Hemisphere, days are shortest and nights are longest June Solstice (20 th or 21 st ) – Earth is tilted toward the Sun; in the Northern Hemisphere, days are longest and nights are shortest March (20 th or 21 st ) and September (22 nd or 23 rd ) Equinox – equal hours of day and night

 The apparent path of the Sun across the sky changes depending on the season

 The accepted hypothesis is that a large object collided with Earth sending large amounts of rock into Earth’s orbit  The rocks clumped together to form the Moon

 Craters  formed by objects impacting the Moon’s surface millions of years ago  Rays  light-colored streaks extending out from craters

 Maria  large, dark, flat areas formed from cooling lava flows  Highlands  the oldest parts of the Moon’s surface covered with craters

 The Moon revolves around the Earth every 27.3 days  The Moon also rotates every 27.3 days  Since the moon’s revolution and rotation are the same, the same side of the Moon always faces the Earth

WAXING PHASES  more of the Moon’s near side is lit each night  First Quarter – western side is lit  Full Moon – entire near side is lit WANING PHASES  less of the Moon’s near side is lit each night  Third Quarter – eastern side is lit  New Moon – entire near side is dark

While the Sun always illuminates the Moon, we can only see a certain portion of the illuminated side depending upon where the Moon is in its orbit around the Earth

 SOLAR ECLIPSES happen when the Moon is between the Earth and Sun and the Moon’s shadow falls on the Earth  They only occur during NEW MOON phase  Umbra  area where the Moon completely covers the Sun  Penumbra  area where the Moon partially covers the Sun

 LUNAR ECLIPSES occur when the Earth comes between the Sun and the Moon and the Earth’s shadow falls on the Moon.  Lunar eclipses happen only during a FULL MOON.  Lunar eclipses DO NOT happen every month, because the Moon’s orbit is tilted 5˚ in relation to the Earth’s orbit  has a reddish tint due to reflected light from Earth, called Earthshine

Tides are the daily rise and fall of sea level due to the gravitational force of the Moon tugging on the Earth. While the Sun’s gravitational force also pulls on the Earth, the Moon’s tug is more effective, because it is closer to Earth A tidal range is the difference between high tide and low tide at a certain location on Earth.

 Spring Tides  The tidal range is the greatest as the Sun, Moon, and Earth are all aligned at 180 o.  occur during full and new Moon phases  produce higher high tides and lower low tides  Neap Tides  The tidal range is the smallest as the Sun, Moon, and Earth are all aligned at 90 o.  occur during first and third quarter Moon phases  produce lower high tides and higher low tides