The Earth, Moon, and Sun Ch. 15

How Does Earth Move? Earth moves in space in two major ways: __________ and __________. –Earth _________ on its _______ (the imaginary line passing through the N & S pole) –Earth _________ around the _______ on an elliptical ________. rotation revolution rotatesaxis revolvessun orbit

How Does Earth Move? The __________ of Earth causes us to have ___________ every ______. The ________ of Earth every ______ ___ causes us to have a _________. rotation day & night 24 hrs revolution 365 ¼ dayyear

The History of the Calendar: ___________: –based their calendar on star motion and calculated about 365 days. They broke them into 12 months with an extra 5 days at the end. Egyptians

The History of the Calendar: __________: –Used the Egyptian calendar but adjusted it to add ¼ of a day (“leap year”). Romans

The History of the Calendar: __________: –The calendar we use today, based off the Roman calendar but adjusted by 11 minutes a year. Named after Pope Gregory XII Gregorian

Planetary Movement

What Causes the Seasons? The sun rays hit’s Earth’s surface ________ (more at the ______ than at the ____). Earth has _______ because its _____ is tilted at ____ degrees as it revolves around the sun. unevenlyEquator poles seasonsaxis 23.5

Earth’s Seasons The sun appears farthest north once a year and farthest south once a year; this is known as the _______. In the Northern Hemisphere when: –the sun is farthest ______ it is the _______ solstice (around ______ 21 st ) and we have the longest day. –the sun is farthest ______ it is the _______ solstice (around ______ 21 st ) and we have the shortest day. Dec. northsummer June southwinter solstice

Earth’s Seasons Halfway between the solstices neither hemisphere is tilted toward the sun, and we have __________in the day and night. This is known as the _______. –the _______ (or spring) occurs around ______ 21 st –the ________ (or fall) occurs around ______ 21 st Sept. equinox vernal March autumnal equal hours

Seasons in the N and S

The Earth & Moon Ch 15 Lesson 2

The Moon Dance

The Moon’s Formation

Rotation and Revolution The Moon rotates on its axis and revolves around the Earth, just as the Earth revolves around the Sun. The Moon’s rotation takes 27.3 days around Earth. It takes about 29.5 days for the Moon to complete the cycle of phases.

Moon Phases Moon phases are the different forms that the Moon takes in its appearance from Earth There are 4 main phases of the Moon: –New: occurs when the Moon is between Earth and the Sun –Waxing: means that more of the half moon can be seen each night –Waning: means that less of the half moon can be seen each night –Full: occurs when all of the Moon’s surface facing Earth reflects light

Moon Phases

Moon Phases…cont.

Eclipses There are two types of eclipses –Solar eclipse: occurs when the Moon moves directly between the Sun and Earth and casts its shadow over part of Earth Umbra: the darkest part of the Moon’s shadow Penumbra: a partial solar eclipse seen from Earth –Lunar eclipse: when Earth’s shadow falls on the Moon

Total Eclipse

Solar Eclipse Lunar Eclipse

The Moon It’s Affect on the Oceans The Earth and the Moon are attracted to each other like magnets. The Earth has a gravitational field that holds objects to it’s surface, but water is always moving therefore can not be held down. Tides are the periodic rise and fall of the ocean waters. High and Low tides occur because of the Moon’s gravitational pull. The ocean moves between high & low tides, about 12 hours 25 minutes b/w the two.

Spring & Neap Tides Spring tide: When the Earth, Moon, and Sun are aligned to cause exceptionally high and low tides. This happens during the Full and New Moon. Neap tide: Smaller difference between high and low tides that occur during quarter phases.

Moon & Tides

H i g h T i d e L o w T i d e

The Importance of Understanding the Tides Commercial and recreational fisherman use their knowledge of tides and tidal currents to help them improve their catches. Ships navigating through shallow water ports and waterways must be knowledgeable of the time and height of the tides as well as the speed and direction of the currents. Oceanographers study tidal fluctuations to better understand the ocean circulation and relationship to world climate issues.