Space Cycle Notes Created by Harris Middle School
Moon A natural satellite of a planet. The outer planets have many of them! Image From: http://sos.noaa.gov/images/Solar_System/moon.jpg; Definition: www.thefreedictionary.com
Lunar Cycle
Full moon: all of surface facing Earth is illuminated (= lit) by the Sun New moon: moon is between Earth & Sun, so lit portion is facing away from Earth Waxing moon: lit portion “growing” Waning moon: lit portion “decreasing” Gibbous moon: larger than ½ (2/3 or ¾ lit) Crescent moon: smaller than ½ (1/3 or ¼ lit) Important to memorize: “Light on the right getting bright”
Can you I.D. these phases? - Where is the sun in this diagram?
Rotation vs. Revolution
Rotation: Revolution: spin of object on its axis rotates counter-clockwise = west to east = why sun appears to rise in the east and set in the west for Earth = 24 hrs. =1 day responsible for day vs. night Revolution: also called an orbit path of one object around another Earth around sun ≈ 365 days = 1 year moon around Earth ≈ 1 month
The TILT is the reason for seasons! The Earth is tilted on its axis by 23.5.° As a result, the hemisphere that is tilted toward the sun receives more direct sunlight = more heat. causes longer daylight hours hotter temperatures = summer! The hemisphere tilted away from the sun experiences winter. The TILT is the reason for seasons!
For the Northern Hemisphere! = least daylight hours = most daylight hours = Equal hours of day and night
Tides Tide = daily rise & fall in ocean water level high and low tides occur twice daily high tides are caused by the gravitational pull of the moon & sun, causing the ocean water to “bulge” away from the Earth the moon has a greater impact because it is closer High tide occurs on the side facing the moon, but it also occurs on the opposite side. This is because the moon is also pulling the Earth away from the water on the other side.
Gravitational pull of the moon Low Tide Tidal bulge High Tide High Tide Gravitational pull of the moon Low Tide
moon and sun pull together = largest tides moon and sun pull against each other = weakest tides