Earth, Moon and Sun The Earth Tilted on an axis (N-S pole) 23.5 degrees Earth moves in space two major ways Rotation- spinning of Earth on its axis West to East, 15 degrees per hour or once per day, counterclockwise This causes day and night—half the Earth is always lit and have it always dark Stars rise in the East and set in the West (btw, stars do not really rise and set, they are stationary, they just look like they are moving, bc the Earth is rotating—this is called apparent motion) Documented with star trails

Earth, Moon and Sun The Earth (cont.) Revolution- Earth’s movement around the sun Earth moves one degree per day One year to complete one revolution around the sun Counterclockwise Evidence of revolution—movement of constellations We see different constellations and different times of the year Ie. Orion can only be seen in the winter Causes Seasons Tilt and curves surface of Earth cause varying amounts of insolation = incoming solar radiation

Earth, Moon and Sun

Earth, Moon and Sun The Moon The Moon revolves around the Earth once every 27.3 days. The Moon also rotates on its axis once every 27.3 days. Because these periods are the same, we only ever see one side of the Moon from Earth. The Moon appears to rise 50 minutes later each night.

Earth, Moon and Sun **Complete the diagram on p. 540 Lunar Phases Only the side of the Moon facing the Sun is illuminated...the other side is dark. When the Moon revolves around the Earth, we see varying amounts of this illuminated side...this is why we see the phases of the Moon. The cycle of phases takes 29.5 days Waxing means the illuminated portion is getting bigger each night. Waning means the illuminated portion is getting smaller each night. **Complete the diagram on p. 540

Earth, Moon and Sun Eclipse Solar Eclipse Occurs during a new moon Moons orbit around Earth is slightly tilted– the moon travels above and below Earth’s orbit On rare occasions, Earth, the moon and the sun line up causing an eclipse Solar Eclipse Occurs during a new moon Moon passes directly between Earth and the Sun, blocking the sunlight from Earth Moons shadow then hits the Earth Umbra- full or darkest part of the shadow Penumbra- partial or larger part of the shadow, people in penumbra see only a “partial” eclipse

Earth, Moon and Sun Solar Eclipse (cont.) Eclipse of 2017: Totality path is 70 mi wide The sun will be completely covered for up to 2 min and 41 sec in some places Last eclipse on mainland 1979 Last total eclipse to cross entire continent of USA 1918 Partial eclipse will last over 2 hours Totality Path Day will seem like night Horizon will look like sunset Stars will be visible Suns’s corona (atmosphere) will be visible

Earth, Moon and Sun Lunar Eclipse Lunar eclipses only occur during the Full Moon phase. A total lunar eclipse is sometimes referred to as a “blood moon” next Jan. 20, 2019 A lunar eclipse occurs when the Earth passes between the Sun and the Moon causing the Moon to be blocked out by the shadow of the Earth. There Earth does create an umbra and penumbra just like in the solar eclipse Unlike the total solar eclipse, a total lunar eclipse can be seen any where on Earth that the moon is visible The next Lunar Eclipse will occur on January 31, 2018 Will be a partial eclipse in New Orleans with max eclipse occurring at 6:47am

Earth, Moon and Sun Tides- the rise and fall of ocean water that occurs about every 12.5 hours 2 High tides per day and 2 low tides per day, each 56 hours apart Gravity pulls the moon and Earth toward each other The gravitational attraction of the moon causes the oceans to bulge out in the direction of the moon.  Another bulge occurs on the opposite side, since the Earth is also being pulled toward the moon (and away from the water on the far side)

Earth, Moon and Sun Tides occur because the moon’s gravity pulls the water closest to it 4 tides occur in 24 hours Each day there are two high tides and two low tides 6 hours between high tide and low tide 12 hours between high tide and the next high tide Spring Tide (has NOTHING to do with the spring season Occurs when the moon, earth and sun are aligned Greatest difference between high and low tide heights

Earth, Moon and Sun Neap Tide Occurs when the line between the moon and Earth form a right angle to the line draw between the Earth and Sun Occurs only during 1st quarter and 3rd quarter moon phases