The Moon

_____Earth’s Satellite_____

Motions of the MoonMoon rotates and revolves

around earth just as earth rotates and revolves around the sun

Takes 27.3 days to make one rotation on its axis.. Same time it takes to make one revolution around earth

Same side is always seen from earth

Moon shines because of reflection of sunlight (half of the moon is always lite)

Phases of the MoonMoon phases are different forms

that the Moon takes in its appearance from earth

Depends on position of earth, moon and sun

New Moon: lighted half of moon is facing the sun and its in the sky during daylight

Moon rises and sets with the Sun

WaxingAfter new moon the moon rises 15

minutes early each night (12° in the sky)Each night you will see more and more

of the moon, beginning with a sliver of moonlight on right side of moon

Called waxing crescent (waxing means adding more and more of the moon to moonlight

After ½ of moon is seen its called first quarter

To Full MoonAfter first quarter its called

waxing gibbousIt continues until the Sun is

opposite in the sky to the moon and we see full reflections of moonlight at night called full moon

Waning PhaseAfter full moon the phases is

called waningMoon is moving on other side of

the earth and the moon begins to lessen in reflection and the moonlight is on the left side of the moon

Waning gibbous lasts till third quarter

After third quarter its called waning crescent till you see a sliver on left side

Waning PhaseTakes 29.5 days for moon to complete its cycle of phases

◦This is due to earth moving around the sun and it takes longer to get to same phase (extra 2 days)

Position of Moon and phases

Cycle From New Moon

EclipsesCause of solar eclipse is when

the moon lines up directly between the earth and sun

The orbit of the moon is not directly lined up with sun and earth, so only see eclipse a few days each year

Solar EclipseMoon moves in between sun and

earth and causes a shadow across the earth

Might be partial or total eclipseDarkest part of moons shadow is

called umbra (will see a total eclipse)

Preumbra is a light shadow on earth’s surface (partial eclipse)

Solar ecplise

Lunar EclipseEarth’s shadow falls on the moonUmbra shadow on earth results in

total eclipsePreumbra shadow is a partial

eclipse as seen on earth

Lunar eclipse

Solar and Lunar Eclipse

Moon’s SurfaceMoon as it cooled was struck by

meteorites and caused cracks in surface that allowed lava to pour out on surface leaving feature called Maria

These features are 3-4 Billion years old.

These are the youngest rocks on moon indicating that the maria formed after the moon’s surface cooled

Inside the MoonCrust about 60 km (40 miles)

thick

1000 km (666 miles down) is the mantle

Lower mantle (partial molten core) with as solid central iron rich core

Origin of MoonBelieved that moon was formed

as result of a collision of Earth with a Mars size object

Debris of condensing gas resulted that organized as the moon