Idaho wildfire as seen by ISS Moon, Moscow, and Aurora From the ISS The Moon What is a moon? A natural planetary satellite A natural planetary satellite Earths Moon Characteristics Mass is 7.3 x kg Mass is 7.3 x kg About 1.2% the mass of Earth About 1.2% the mass of Earth Radius 1700 km Radius 1700 km About 27% the size of Earth About 27% the size of Earth Surface Gravity 17% or 1/6 that of Earth Surface Gravity 17% or 1/6 that of Earth Moon Characteristics The average temperature on the Light side of the moon is 394 K (123 Celsius, 253 Fahrenheit). The average temperature on the Light side of the moon is 394 K (123 Celsius, 253 Fahrenheit). The average temperature on the Dark side of the moon 40 K (-233 Celsius, -387 Fahrenheit). The average temperature on the Dark side of the moon 40 K (-233 Celsius, -387 Fahrenheit). Moon Characteristics The mineral and element content of the moon is different from that of Earth. The mineral and element content of the moon is different from that of Earth. Iron is prevalent on the surface and in the mantle of Earth, but rare on the moon. Iron is prevalent on the surface and in the mantle of Earth, but rare on the moon. Other elements, like Helium-3 are prevalent on the moons surface, but not on Earth. Other elements, like Helium-3 are prevalent on the moons surface, but not on Earth. Moon Characteristics In September of 2009, the NASA LCROSS probe released an impacter which crashed into the lunar south pole In September of 2009, the NASA LCROSS probe released an impacter which crashed into the lunar south pole Moon Characteristics The resulting debris cloud contained a variety of compounds, including H 2 O The resulting debris cloud contained a variety of compounds, including H 2 O Longtime speculation was confirmed, there is ice in the shadowed craters of the polar regions of the moon Longtime speculation was confirmed, there is ice in the shadowed craters of the polar regions of the moon Theories of the Moons Formation Fission Fission Capture Capture Binary Accretion Binary Accretion Collision-ejection theory Collision-ejection theory Collision-ejection theory Collision-ejection theory Probably Wrong Fission Theory A mass of material split off from the Earth as it was cooling and formed into the moon. A mass of material split off from the Earth as it was cooling and formed into the moon. Capture Theory A large asteroid was pulled into orbit around the earth and became the moon A large asteroid was pulled into orbit around the earth and became the moon Binary Accretion A ring of dust developed around the Earth as it was cooling, eventually coalescing and forming into the moon. A ring of dust developed around the Earth as it was cooling, eventually coalescing and forming into the moon. Collision-ejection theory Collision-ejection theory proposes that the Earth was struck by a Mars-size object within the first 100 million years after our planet formed. proposes that the Earth was struck by a Mars-size object within the first 100 million years after our planet formed. Lunar Surface The surface of the moon is covered with impact craters. The surface of the moon is covered with impact craters. Impact craters are caused by celestial objects, mostly asteroids and meteoroids, hitting the moons surface. Impact craters are caused by celestial objects, mostly asteroids and meteoroids, hitting the moons surface. Shaping Planetary Surfaces Impact Cratering Why does the Earth have so few craters? Answers: Answers: Erosion Erosion weathering, tectonics weathering, tectonics Atmosphere Atmosphere small meteors burn up on entry small meteors burn up on entry Lunar Surface Large moon impact craters that were created billions of years ago by asteroids. Large moon impact craters that were created billions of years ago by asteroids. For many craters you will see long, light streaks of pulverized rock called rays. For many craters you will see long, light streaks of pulverized rock called rays. You can also see lunar canyons called rilles. You can also see lunar canyons called rilles. Maria The large, smooth, dark areas on the Moon are called maria (MAR-ee-a), from the Latin word for "seas". The large, smooth, dark areas on the Moon are called maria (MAR-ee-a), from the Latin word for "seas". The singular form is mare (MAR-ay). The singular form is mare (MAR-ay). Example: Mare Tranquilitatis is the "Sea of Tranquility". Example: Mare Tranquilitatis is the "Sea of Tranquility". Lunar Maria Basalts Lunar Highlands Breccias Lunar Missions The Lunar Surveyor spacecrafts were among the first to reach the moons surface. The Lunar Surveyor spacecrafts were among the first to reach the moons surface. There were 6 manned missions to the lunar surface. There were 6 manned missions to the lunar surface. 12 Americans during the Apollo program 12 Americans during the Apollo program Lunar Prospector Lunar Topography 2011 The 6 Moon Landings Lunar Missions In September 2009, the LCROSS probe discovered the present of frozen water on the poles of the moon. In September 2009, the LCROSS probe discovered the present of frozen water on the poles of the moon. This is considered by NASA to be a target area for future lunar exploration and / or moon base. This is considered by NASA to be a target area for future lunar exploration and / or moon base. The Moon has a synchronous rotation. The Moon has a synchronous rotation. This means that we only see one side of the Moon from the Earth. This means that we only see one side of the Moon from the Earth. Does the moon rotate? Does the moon rotate? Yes Yes Is the farside always dark? Is the farside always dark? No No Is the a part of the moon that we never see? Is the a part of the moon that we never see? Yes...but... Yes...but... The Moons Far Side The Moons Near Side Tides What causes tides on Earth? The pull of gravity by the moon as the Earth rotates about its axis In general, it take for the tides twelve hours to cycle on Earth. The difference in gravitational forces accounts for the tides; this tidal force tends to pull bodies apart. Tides Halls Harbour on Nova Scotia's Bay of Fundy Halls Harbour on Nova Scotia's Bay of Fundy Tides Spring Tides Spring Tides When the moon is full or new, the gravitational pull of the moon and sun are combined. At these times, the high tides are very high and the low tides are very low. This is known as a spring high tide. When the moon is full or new, the gravitational pull of the moon and sun are combined. At these times, the high tides are very high and the low tides are very low. This is known as a spring high tide. Tides Neap Tides Neap Tides During the moon's quarter phases the sun and moon work at right angles, causing the bulges to cancel each other. The result is a smaller difference between high and low tides and is known as a neap tide. During the moon's quarter phases the sun and moon work at right angles, causing the bulges to cancel each other. The result is a smaller difference between high and low tides and is known as a neap tide. Tides Is the moon the only factor that influences the tides on Earth? Is the moon the only factor that influences the tides on Earth? No but it is the greatest No but it is the greatest What could be some other factors? What could be some other factors? Lecture Quiz! Get out a piece of notebook paper, write your name at the top and print The Moon at the top of the sheet.