Post on 20-Jan-2016
Observed Phases of the Moon
R. Rogers, Nov 29, 2011
8th
Grade Science
ButlerMiddleSchool
Full moon on Dec 10
Tonight Nov 29
Phases of the Moon as it revolves around the Earth
They always follow one another in the same order
Sun
Why does the Moon change shape?
•From day to day we view the bright part of the moon’s surface from different angles so it appears to change shape as it revolves around us
•The different shapes, called phases, depend on how much of the illuminated half of the moon faces earth
New and Full Moons
• We would expect a new moon to block sunlight from hitting the earth
• We would expect the earth to block sunlight from reaching a full moon
• However, we only see the expected once in a great while
SunLight
New
Full
Motion of Moon and Earth Orbital plane of moon is tilted 5º from earth’s orbital plane, this causes a misalignment of the earth, moon, and sun
Eclipse
• Once in awhile, the earth, moon, and sun do "line up”, this is called an eclipse
• Eclipses are rare– Roughly 4 to 7 occur in any given year, but most of
them are minor or "partial" eclipses.
• They can occur two ways– Solar Eclipse– Lunar Eclipse
Solar Eclipse – Only during a New Moon
The moon casts a shadow on the Earth, people in shadow experience a brief period of darkness during the day
Actual Solar Eclipse
Partial Total
moon
Lunar Eclipse – Only during a Full Moon
The earth casts a shadow on the full moon
Actual Lunar Eclipse• Sequence of photos showing Earth’s
shadow on the Moon
Solar Eclipse
Lunar Eclipse
Sun M E
Sun E M
Next Eclipse?