The Earth, Moon, and Sun Ch. 15

1. The Earth, Moon,and SunCh. 15

2. 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 ________. revolution rotation rotates axis revolves sun orbit

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

4. The History of the Calendar: Egyptians • ___________: • 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.

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

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

7. Planetary Movement

8. 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. unevenly Equator poles seasons axis 23.5

10. 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 ______ 21st) and we have the longest day. • the sun is farthest ______ it is the _______ solstice (around ______ 21st) and we have the shortest day. solstice north summer June south winter Dec.

11. 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 ______ 21st • the ________ (or fall) occurs around ______ 21st equal hours equinox vernal March autumnal Sept.

13. Seasons in the N and S

14. The Earth & Moon Ch 15 Lesson 2

15. The Moon Dance

16. The Moon’s Formation

17. 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.

18. 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

19. Moon Phases

20. Moon Phases…cont.

21. 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

22. Total Eclipse

23. Lunar Eclipse Solar Eclipse

25. The MoonIt’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.

26. Spring & Neap Tides Neap tide: Smaller difference between high and low tides that occur during quarter phases. 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.

27. Moon & Tides

28. Low Tide High Tide

29. 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.