- Slides: 28
Phases of the Moon
Phases of the Moon • The first astronomical event to be understood was the regular cycle of the phases of the moon. • On a monthly basis, we observe the phases of the moon as a change in the amount of the moon that appears lit. http: //www. google. com/imgres? sa=X&biw=1093 &bih=496&tbm=isch&tbnid=8 h. O 020 phy. Rz. Et. M% 3 A&imgrefurl=http%3 A%2 F%2 Fblog. boatpeopleb outique. com%2 Fdiy-moon-phasesjacket&docid=Ilg 5 QSWwh. X 61 M&imgurl=http%3 A%2 F%2 Fblog. boatpeopleb outique. com%2 Fwpcontent%2 Fuploads%2 F 2013%2 F 03%2 FPhasesm oon. jpg&w=1600&h=687&ei=y. LPz. Uos 3 q. YTIAamf g. K&zoom=1&ved=0 CGw. Qh. Bww. CA&iact=rc&d ur=292&page=1&start=0&ndsp=9
Phases of the Moon • Look at the new moon shown in the figure. • About two days after the new moon, a thin sliver (crescent phase) appears low in the western sky just after sunset.
Phases of the Moon • During the following week, the lighted portion of the moon visible from Earth increases (waxing) to a half circle (firstquarter phase) and can be seen from about noon to midnight.
Phases of the Moon • In another week, the complete disk (full-moon phase) can be seen rising in the east as the sun is sinking in the west. • During the next two weeks, the percentage of the moon that can be seen steadily declines (waning), until the moon disappears altogether (new-moon phase)
In the box draw and label each moon phase
Phases of the Moon • Lunar phases are a result of the motion of the moon and the sunlight that is reflected from its surface. • To an observer on Earth, the percentage of the bright side that is visible depends on the location of the moon with respect to the sun and Earth.
Phases of the Moon • When the moon lies between the sun and Earth, none of its bright side faces Earth. • This is a new moon. https: //www. google. com/imgres? imgurl&imgrefurl=http%3 A %2 F%2 Fwww. moonconnection. com%2 Fmoon_phases. phtml &h=0&w=0&sz=1&tbnid=OBSu. Whzo 7 Tpmn. M&tbnh=213&tbn w=237&zoom=1&docid=ap. GI 7 Ypo. Fy. NNM&ei=ic. Lz. Uq. Ss. CLHgs. ASfl. IHg. Dg&ved=0 CAIQs. CUo. AA
Phases of the Moon • After the new moon comes the waxing crescent. (a crescent shape can be seen lit on the right side).
Phases of the Moon • After the waxing crescent comes a first quarter moon in which the right half of the moon appears lit.
Phases of the Moon • Following the first quarter is the waxing gibbous • The moon is in gibbous phase when more than half of it is lit.
Phases of the Moon • Following waxing gibbous is the full moon phase in which the entire side of the moon facing Earth appears lit. • From full moon the cycle moves to waning gibbous – The bulge appears on the left.
Click photo for video • From waning gibbous, the moon moves into 3 rd quarter – the left half of the moon appears lit. • From 3 rd quarter the moon moves into waning crescent, and finally back to new moon.
Eclipses • A lunar eclipse occurs when the Earth passes between the Moon and the Sun, and the Earth's shadow obscures the moon or a portion of it. • Only occur during full moon phases when Earth is between the sun and moon http: //www. google. com/imgres? biw=942&bih=4 28&tbm=isch&tbnid=Motb. GDGv. M 6 Jqn. M%3 A&i mgrefurl=http%3 A%2 F%2 Fstarryskies. com%2 FTh e_sky%2 Fevents%2 Flunar 2003%2 Feclipse 1. html&docid=dj 07 b 0 ZLc. E 16 VM &imgurl=http%3 A%2 F%2 Fstarryskies. com%2 FTh e_sky%2 Fevents%2 Flunar 2003%2 Flunar. eclipse 01. jpg&w=571&h=283&ei= bs. IGU-Pd. Dbm 2 AWjj 4 C 4 Dg&zoom=1&ved=0 CLo. BEIQc. MBk& iact=rc&dur=279&page=3&start=14&ndsp=12
Eclipses • A solar eclipse occurs when the Moon passes between the Earth and the Sun, blocking all or a portion of the Sun. http: //www. google. com/imgres? sa=X&biw=942&b ih=428&tbm=isch&tbnid=VFjfm. DRpqtt. XM%3 A&imgrefurl=http%3 A%2 F%2 Fqcw eather. blogspot. com%2 F 2012%2 F 05%2 Fsolareclipse. html&docid=i. Ed. YVg 1 Hj 1 JTBM&imgurl=http %3 A%2 F%2 F 3. bp. blogspot. com%2 Fz 67 z. XPIEu. KM%2 FT 7 h. Uiiv. V 8 q. I%2 FAAAADOY %2 FENRd. RQ 8 Mj. M%2 Fs 1600%2 Feclipse 1. JPG&w=720&h=486&ei= 18 EGU 6 uh. Oa. Wi 2 QX 41 o. Hw. Bg&zoom=1&ved=0 CLo BEIQc. MB 8&iact=rc&dur=458&page=3&start=20&n dsp=12
Umbra and Penumbra • Because the Sun appears as a disk ~1/2° across, Sun shadows are fuzzy rather than sharp. • This means shadows cast by the Earth & Moon are two -part shadows: The Umbra - Inner core of total darkness The disc of the Sun is completely blocked. The Penumbra - Outer, partial shadow Sun's disc is only partly blocked, with a bit peeking over the edge.
Click for Eclipse Video
• http: //www. moonconnection. com/lunar_vs_s olar. phtml • http: //www. astronomy. ohiostate. edu/~pogge/Ast 161/Unit 2/eclipses. html