Moons of the solar system, as of Moons of the solar system, as of October ,2011October ,2011

PlanetPlanet Number of Number of MoonsMoons

MercuryMercury 00

VenusVenus 00

EarthEarth 11

MarsMars 22

JupiterJupiter 6060

SaturnSaturn 3131

UranusUranus 2727

NeptuneNeptune 1313

PlutoPluto 11

Earth’s MoonEarth’s Moon

Possible Origin (theories)......Possible Origin (theories)......

Formed Apx. 4.6 billion years ago.Formed Apx. 4.6 billion years ago. Collision between a Earth and Mars-size Collision between a Earth and Mars-size

object.object. Impacts create the geologic features we Impacts create the geologic features we

see today.see today.

Geology ……Geology ……

Mares (seas) - lava filled basins or low Mares (seas) - lava filled basins or low lands on the moon…..(darker regions).lands on the moon…..(darker regions).

Highlands – rimmed portions of the craters Highlands – rimmed portions of the craters or mountainous areas….(lighter regions). or mountainous areas….(lighter regions).

Phases….Phases….

Phases – daily change in appearance.Phases – daily change in appearance. This occurs for 2 reasons;This occurs for 2 reasons;

Moon is seen by reflected light…Moon is seen by reflected light… Moon is in orbit around the Earth… Moon is in orbit around the Earth…

NOTE – It takes the moon 27.3 days to revolve NOTE – It takes the moon 27.3 days to revolve around the Earth.around the Earth.

Phases diagram..Phases diagram..

Waxing = when the moon goes from New Waxing = when the moon goes from New to Full.to Full.

Waning = when the moon goes from Full Waning = when the moon goes from Full to New.to New.

What does the moon do?What does the moon do?

Tides Tides The moon is The moon is

responsible for the responsible for the TidesTides – – Daily rise and Daily rise and fall of sea level (NOT fall of sea level (NOT WAVES).WAVES).

Tides cont……Tides cont……

High tide to Low tide = 6hrs, 12 min, 30 sec.High tide to Low tide = 6hrs, 12 min, 30 sec. Tidal Range – difference between High and low Tidal Range – difference between High and low

tide. tide.

Shadows……..Shadows……..

Umbra- total shadow..Umbra- total shadow..

Penumbra – partial Penumbra – partial shadow…..shadow…..

Types of eclipses……Types of eclipses……

Lunar eclipse - Lunar eclipse - occurs when the occurs when the moon is full and passes in the moon is full and passes in the

Earth’s shadow…..Earth’s shadow…..

Solar eclipse - Solar eclipse - occurs when the moon is new, and the occurs when the moon is new, and the Earth passes through the moons Earth passes through the moons shadow…….shadow…….NOTE: Must be at perigee…..NOTE: Must be at perigee…..