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From Galileo. Earth Without the Moon. Michelle Kirchoff Southwest Research Institute Center for Lunar Origin and Evolution. Gravity - Acceleration. Acceleration due to gravity ( g ) is directly related to mass. M. m. Gravity - Acceleration.
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Earth Without the Moon Michelle Kirchoff Southwest Research Institute Center for Lunar Origin and Evolution
Gravity - Acceleration • Acceleration due to gravity (g) is directly related to mass M m
Gravity - Acceleration • Acceleration due to gravity (g) is directly related to mass • And is indirectly related to the radius squared M m r
Gravity - Accleration • GXM(Earth)/[R(Earth)XR(Earth)] = g(Earth) • 6.7*10-11 X 6*1024kg/[6370000m X 6370000m] = 9.8 m/s2 • GXM(Moon)/[R(Moon)XR(Moon)] = g(Moon) • 6.7*10-11 X 7*1022kg/[1740000m X 1740000m] = 1.7 m/s2
Gravity - Force • force between two bodies (F) is directly related to the acceleration of the first and the mass of the second M m F F
Gravity - Force GXM(Earth)XM(Moon)/[D(Earth-Moon)XD(Earth-Moon)] = F 6.7*10-11 X 6*1024kg X 7*1022kg/[380000000m X 380000000m] = 2*1020 N = 4.5*1019 lbs F (Earth – Sun) = 4*1022 N Earth – Moon distance = 240 thousand miles (ND ~ 340 miles)
If there was no Moon… • Seasons and climate erratic => Moon stabilizes tilt of Earth’s rotational axis
If there was no Moon… • Much smaller tides => 1/3 today (tidal force = gradient of Graviational Force => indirectly related to radius cubed Moon Sun
If there was no Moon… • Earth spins faster => ~ 8 hrs instead of 24