# A Closer look at Our Moon Created by:

A Closer look at Our Moon Created by: Mrs. BodineDonahue The moon is a natural satellite. A satellite is anything the orbits the earth. Artificial satellites have four main

uses: Communications Monitoring the weather Observing the Earth Exploring the solar system The moon is a cold, dry orb whose surface is studded with craters and strewn with rocks and dust. The moon has no atmosphere. Recent lunar missions indicate that there might be some

frozen ice at the poles. The Moons movement The moon revolves around the Earth in about one month (27 days 8 hours). It rotates around its own axis in the same amount of time. The same side of the moon always faces the Earth; it is in a synchronous rotation with the

Earth. The Moons Orbit The Moon and Earth both orbit around a point between their centers called the center of mass of the Earth-Moon system

The center of mass then follows an elliptical orbit around the Sun This Picture Distorts the Earth-Moon Distance An Everyday Example of Center of Mass Motion

Motion of the Earth-Moon Center of Mass How far away is the Moon? The moon is about

238,900 miles (384,000 km) from Earth on average. At its closest point the moon is 221,460 miles (356,410 km) from the Earth. At its farthest approach the moon is 252,700 miles

(406,700 km) from the Earth. Size of the Moon The moon's diameter is 2,140 miles (3,476

km), the Earth is 7,900 miles (12,742 km) in diameter. That's how far you would have to tunnel to dig to the other side of the Earth! The circumference of the moon is 6,790 miles

(10,864 km). The circumference of the earth at the equator is 24,901.55 miles (40,075 km). How much does the Moon weigh? The moon's mass is about 1/81 of the

Earth's mass. The moon's gravitational force is only 17% of the Earth's gravity. For example, a 100 pound person would weigh only 17 pounds on the Moon. The Atmosphere on the

Moon TEMPERATURE The temperature on the Moon ranges from daytime highs of about 130C = 265F to nighttime lows close to -310 F. ATMOSPHERE The moon has no atmosphere. On the moon, the sky is always appears dark, even on the bright side (because there is no atmosphere). Also, since sound waves

travel through air, the moon is silent; there can be no sound transmission on the moon. Craters The surface of the moon is scarred by millions of (mostly circular) impact craters, caused by

asteroids, comets, and meteorites. There is no atmosphere on the moon to help protect it from bombardment from potential impactors (most objects from space burn up in our atmosphere). Also,

there is no erosion (wind or precipitation) and little geologic activity to wear away these craters, so they remain unchanged The Moons airless, dry surface is covered with plains and craters

The Earth-facing side of the Moon displays light-colored, heavily cratered highlands and dark-colored, smooth-surfaced maria The Moons far side

has almost no maria Another View of the Moon The Moons Surface Close up Virtually all lunar

craters were caused by space debris striking the surface

There is no evidence of plate tectonic activity on the Moon The maria formed after the surrounding light-colored terrain, so they have not been exposed to meteoritic bombardment for as long and have fewer craters

Human exploration of the lunar surface Much of our knowledge about the Moon has come from human exploration in the 1960s and early 1970s and from more recent observations by unmanned

spacecraft Man on the Moon There have been 6 missions to the moon, including orbiters missions and moon landings. On July 20, 1969 Neil Armstrong was the first person to set foot on the moon. His first words upon stepping down the Lunar Module's ladder onto the lunar

surface were, "That's one small step for man, one giant leap for mankind." Aldrin described the lunar scenery as "magnificent desolation." 12 astronauts have walked on the moon. All were American. How did the Moon form? Most scientists believe that the moon was formed from the ejected material after the

Earth collided with a Mars-sized object. This ejected material gathered into the moon that went into orbit around the Earth. This catastrophic collision occurred about 60 million years after Earth itself formed (about 4.3 billion years ago). This is determined by the dating of moon rocks. Meteoroid impacts have

been the only significant erosion agent on the Moon The Moons regolith, or surface layer of powdered and fractured

rock, was formed by meteoritic action All of the lunar rock samples are igneous rocks formed largely of minerals found in terrestrial rocks Mare basalt

The lunar rocks contain no water They differ from terrestrial rocks in being relatively enriched in the refractory elements and depleted in the volatile elements Highlands

anorthosite Impact breccia Lunar rocks reveal a geologic history quite unlike that of Earth The anorthositic crust exposed in the highlands was formed between 4.0

and 4.3 billion years ago The mare basalts solidified between 3.1 and 3.8 billion years ago The Moons surface has undergone very little change over the past 3 billion years The Moon has no global magnetic field but has

a small core beneath a thick mantle Source: Dr. James Regas Cal State Chico Source: Dr. James Regas Cal State Chico Source: Dr. James Regas Cal State Chico Source: Dr. James Regas Cal State Chico

Most Likely Theory of Formation of the Moon The collisional-ejection theory Successfully explains most properties of the Moon Hypothesizes that the proto-Earth was struck by a Mars-sized protoplanet and that debris from this collision coalesced to form the Moon The Moon was molten in its early stages, and the anorthositic crust solidified from low-density magma that floated to the lunar surface

The mare basins were created later by the impact of planetesimals and filled with lava from the lunar interior Other alternate theories that fail in areas Co-creation (sister), fission, capture Why would it be difficult to live on the moon? Why would we want a space station on the

moon? Source: Dr. James Regas Cal State Chico Source: Dr. James Regas Cal State Chico Source: Dr. James Regas Cal State Chico

## Recently Viewed Presentations

• Cells Regions of cells Middle lamella = pectin Bacteria/fungi break down causing fruit/vegetable rot Like "mortar" between two bricks! Primary cell wall = cellulose and pectin Secondary cell wall = cellulose and lignin (not always present) Pectin Rot in fruit...
• Training is distinguished from education by its characteristics of practicality, specificity, and immediacy. Education is a broader concept that is more philosophical and theoretical in nature than training. Twelve: Education and Training Corporate training in the United States has historically...
• BASIC IDEAS. Shapes of molecules and ions depends on total number of electron pairs around the central atom. Two types of electron pairs: Bonding pairs (i.e. e
• lessons learned from past notable disasters ... and construction adequacy of lateral-force resisting system vulnerability is the ultimate cause of risk unreinforced masonry, brick or stone reinforced concrete with unreinforced walls intensity reinforced concrete with reinforcedwalls steel frame ...
• Fiber to the antenna for both indoor and outdoor environments. ... Potential life cycle issues when deploying outdoor microduct. Flexible microduct life span is less than 2 years. ... De-skills installation requirement. Stage 2 : Fibre to the floor ...
• Dr. Wonderful, Dr. Rigid, Dr. Line Crosser, Dr. Dippy, and Dr. Evil All Mixed Up 2 300 What is the mind-body debate? The debate about what the mind is, what the mind is made of, and if the mind is...
• Bukod dito, may mga panlaping sadyang ginagamit sa bawat pokus. Upang makilala sa loob ng pangungusap ang paksa, tandaan na ang paksa ay pinangungunahan ng mga panandang paksa, gaya ng ang, ang mga, at si at sina. 1. Pokus sa...
• Norsk Pedagogisk Tidsskrift, nr 1,2008, side 14.26, Universitetsforlaget. Black,P&William,D.(1998) Inside the Black Box -raising standards through classroom assessment:London School of Education, King's College A well-done rubric is both an instructional tool and an assessment mechanism.