How the moon affects earth.

Motions of the moon

• The moon rotates on its axis once every 27.3 days.

• The moon revolves around the earth once every 27.3 days.

• Therefore, a “day” and a “year” on the moon are the same length!

• The same side of the moon, the near side, always faces earth. We never see the far side of the moon.

Phases of the moon

• The different shapes of the moon that we see from earth are called its phases.

• Phases are caused by the position of the earth, moon and sun and those positions change every day.

• The phase of the moon we see depends on the amount of the sunlit side of the moon that faces earth.

• Moon phases-moon phases code cfp 5013

tides

• The rise and fall of oceans’ water every 12.5 hours.• Caused by the differences in how much the moon’s

gravity pull on different parts of the earth.• Spring tides- greatest difference in low and high tides.

Occurs when sun, moon and earth are aligned in a straight line.

• Neap tides- least difference in low and high tides. Occurs when moon is at right angles to earth and sun.

• Animation: http://www.sfgate.com/getoutside/1996/jun/tides.html

eclipses• When the shadow hits Earth or moon’s Earth’s shadow hits the

moon, an eclipse occurs.• Eclipse-caused when an object in space comes between the sun

and another objects, casting a shadow on that object.• Solar eclipse- occurs at the new moon phase when the moon

passes between Earth and the sun, blocking the sunlight from reaching Earth.

• Animation of solar eclipse:• http://www.teachersdomain.org/resources/ess05/sci/ess/eiu/

totaleclipse/index.html• Lunar eclipse- occurs at a full moon when Earth is directly between

the moon and the sun.• Animation of a lunar eclipse:• http://www.classzone.com/books/earth_science/terc/content/

visualizations/es2504/es2504page01.cfm?chapter_no=visualization