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The Moon. Size Comparison. How did we get there and why?. The Moon and Earth to shown scale and distance. Who am I?. Neil Armstrong. The first human being to walk on the Moon. What did I say? This is one small step for a man, one giant leap for mankind. Who am I?. Alan Shepard.
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Size Comparison How did we get there and why?
Neil Armstrong The first human being to walk on the Moon. What did I say? This is one small step for a man, one giant leap for mankind.
Alan Shepard Born and grew up in Derry, NH. Original Mercury astronaut, the first American in space during a suborbital flight reaching 116 miles altitude on 5th May 1961. He also commanded Apollo 1 mission to the moon, from 31st January to 9th February 1971, the third lunar mission.
Gravity or gravitational forces exist when one object attracts another. It's like the Earth pulling on you and keeping you on the ground. That's gravity at work. Every object in the universe that has mass has a gravitational force. Even you exert gravity. When you compare your mass to the mass of the Earth, your gravitational force is very weak compared to the Earth’s. Other planets also affect our world. Our connection to the Moon's gravity makes the tides rise and fall. The Earth's gravity keeps our planet orbiting the Sun, just like the Sun's gravity pulls on our planet. "What about feathers? They fall so slowly." Obviously, there is air all around us. When a feather falls, it falls slowly because the air is in the way. There is a lot of resistance and that makes the feather move slower. The forces at work are the same. If you dropped a feather in a container with no air on Earth, the feather would drop just as fast as a hammer.
1st Theory: Giant Impact Hypothesis for the Origin of the Moon
4 Theories of Formation 1st Theory Giant Impact Hypothesis: A Mars sized object slammed into the Earth over 4 billions years ago blasting a ring on material similar to what is found on the surface of the Earth this material condensed to form the moon. 2nd Theory Moon Capture Theory: a ring of dust around earth slows the passing moon, allowing it to be captured by Earth's gravity. 3rd Theory Sister Theory: the Earth and the moon were formed at the same time as the solar system formed. 4th Theory fission Theory: The early Earth was spinning so fast part of it broke off due to centrifugal force and formed the moon.
Moon details • Diameter: 2,160 mi • Rotation Period: 27.3 days • Revolution Period: 27.3 days • The Earth’s gravity has locked the moon into a Synchronous Rotation • Distance from Earth: 240,000 miles away • Surface Temp: 250°F during the day to -280°F during the night • About 4.5 billion years old
Density • 3/5 Earth’s density- poor quantities of metal on the moon • Surface gravity is 1/6 Earth’s (due to small mass and size) • How much would a 180 lb person weigh on the moon?
CRATERS The diameter of this crater is about 58 miles wide.
Phases of the Moon • Like the Earth, moon is always half illuminated by the sun. • During each lunar month we see the moon’s appearance change from not visibly illuminated to fully illuminated then back again. • A complete phase cycle take 29.5 days to complete
Sidereal vs. Synodic Months The moon takes 27.3 days to go around the Earth but the phases of the moon occur in 29.5 day cycles. This is because as the moon circles around the Earth, the Earth also moves around the sun, so it takes an extra 2.2 days for the sun’s light to hit the moon from the same angle. A Sidereal Monthis the time the moon takes to complete one full revolution around the Earth or 27.3 days. The Earth is constantly moving on its orbit around the Sun, the moon must travel slightly more than 360° to get from one new moon to the next. A Synodic Month, or lunar month, is longer than the sidereal month an is the time between moon phases which last 29.5 days.
Influenced mostly by the Moon’s gravity. • We see two tidal bulges on Earth, one on the near side (closest to the moon) and one on the far side. • Because Earth is rotating, bulges are swept forward. • A place on the Earth’s surface experiences high tide when that place faces toward or away from the Moon. Low tide occurs when the Earth has rotated 90° from high tide • During a span of approximately 24 hours, every location on Earth passes through 2 high tides and 2 low tides Tides
Eclipses • Lunar eclipse- When the sun casts Earth’s shadow on the moon because the Moon moves directly behind the line between the Sun and Earth • Solar eclipse- When the sun casts Moon’s shadow on Earth because the Moon moves between the Sun and Earth.
Review Time • Who was the first American in space? • Who was the first person to set foot on the moon? • When did we reach the moon? • Why do a feather and hammer fall at the same rate on the moon? • Why will the foot prints on the moon remain unchanged? • What are the two types on months and how are they different? • What is a solstice and equinox and when do they occur?
More Review • What causes the tides? • What is a neap tide and spring tide and when do these occur? • What cause the moon to change phases? • What causes solar and lunar eclipses? • What are theories about where the moon come from? • What are three benefits of moon soil?
Up coming blue moons • 2010 Nov 21 • 2013 Aug 21 • 2016 May 21 • 2019 May 18 & Feb 19 • 2021 Aug 22 & Nov 19 • 2024 Aug 19 • 2027 May 20 & Feb 20