# The Earth & Moon System.

## Presentation on theme: "The Earth & Moon System."— Presentation transcript:

The Earth & Moon System

The Earth Properties Earth is a sphere
Aristotle believed the Earth was round because of the shadow cast on the Moon during a lunar eclipse. (circa 350 B.C.) Earth bulges slightly at the equator & is somewhat flattened at the poles.

Rotation The amount of time it takes an object to make one full spin on its axis. Rotation causes day & night. Earth’s rotation is 23 hrs, 56 min

Revolution The amount of time it takes for one object to make one full trip around another larger object in space. The orbit path is elliptical. Earth’s revolutionary period is days

Protects Earth from some of the solar radiation.
Magnetic Field The movement of Earth’s core material & Earth’s rotation generates a magnetic field. Protects Earth from some of the solar radiation. The magnetic axis is inclined at 11.5o from the rotational axis. The distance between the Earth and its moon averages about 238,900 miles (384,000 kilometers). The diameter of the moon is 2,160 miles (3,476 kilometers).

Earth’s axis is tilted 23.5o
The Seasons Earth’s Orbit & Tilted Axis Whether the Earth is closer to the Sun or further away has NOTHING to do with its seasons. Earth’s axis is tilted 23.5o The tilting of the axis results in part of the Earth receiving more direct sunlight at times causing the seasons.

Solstices The day when the Sun reaches its greatest distance north or south of the equator. The summer solstice is the 1st day of summer and has the longest number of daylight hours during the year. The winter solstice is the 1st day of winter and has the shortest number of daylight hours during the year.

1st day of autumn & spring.
Equinoxes The two days out of the year when the Sun is directly over the equator. 1st day of autumn & spring. The number of daylight hours are nearly equal all over the world. Neither hemisphere is tilted toward the Sun.

How did the moon form? According to the "giant impact" theory, the young Earth had no moon. At some point in Earth's early history, a rogue planet, larger than Mars, struck the Earth in a great, glancing blow. Instantly, most of the rogue body and a sizable chunk of Earth were vaporized. The cloud rose to above 13,700 miles (22,000 kilometers) altitude, where it condensed into innumerable solid particles that orbited the Earth as they aggregated into ever larger moonlets, which eventually combined to form the moon. The Moon is 4.5 billion years old.

The Moon Rotation period = 27.3 days Revolutionary period = 27.3 days
+ The distance From Earth is 363,301 kilometers (225,745 miles). Motions of the Moon Rotation period = 27.3 days Revolutionary period = 27.3 days Since both motions are the same, the same side of the Moon ALWAYS faces the Sun. This produces the phases of the Moon. If the moon were placed on the surface of the continental United States, it would extend from San Francisco to Cleveland (2,600 miles)

Each phase is determined by the positions of the Earth, Moon, & Sun.
Phases of the Moon Each phase is determined by the positions of the Earth, Moon, & Sun. Waxing occurs when the lighted side of the Moon begins to show more & more. Waning occurs when the lighted side becomes less and less.

The thin sliver of the lighted side is called a Waxing Crescent.
When the right half of the lighted side is showing, its called a 1st Quarter Moon. When more than half of the lighted side is showing, its called a Waxing Gibbous. A Full Moon occurs when all of the lighted side of the Moon is showing.

A New Moon occurs when the Moon is between the Sun & Earth
A New Moon occurs when the Moon is between the Sun & Earth. The dark side of the Moon faces the Earth while the lighted side faces the Sun. The moon is not up during the night. A Waning Gibbous occurs after the Full Moon. When the left half of the Moon is showing, a 3rd Quarter Moon occurs. A Waning Crescent occurs next followed by the New Moon again.

Eclipses Solar Eclipses The Moon, during the New phase, blocks the Sun by passing in front of it. The shadow cast on the Earth by Moon during the eclipse is called the umbra. A total eclipse is seen here. A partial eclipse is seen in the penumbra, which is a lighter shadow.

SOLAR ECLIPSE Penumbra Umbra

Lunar Eclipse The Earth passes between the Sun & Moon. The Earth casts its shadow on the surface of a Full Moon. Light passing through the Earth’s atmosphere during a total lunar eclipse can sometimes make the Moon turn red. More common than solar eclipses. + Do you know the moon’s name? It’s Luna.

The word "lunatic" comes from when doctors thought that the insane were "moonstruck."

Penumbra Umbra Lunar ECLIPSE

The Moon’s Surface & Interior
Lunar Surface No atmosphere Covered in craters caused by meteor impacts. Dark, flat regions made of basaltic lava flows are called maria (mare.)

The core may be solid & iron-rich.
Lunar Interior Crust of the light side of the Moon might be thinner than the dark side of the Moon. The upper mantle of the Moon is solid with a partially melted lower mantle. The core may be solid & iron-rich. The moon is actually moving away from earth at a rate of 1.5 inches per year. The temperature on the Moon reaches 243° F at midday on the lunar equator. During the night, the temperature falls to -261° F.

Exploring the Moon “We choose to go to the Moon.”-JFK Project Mercury
Goal: orbit a piloted spacecraft around the Earth and bring it back safely. Alan B. Sheppard was the 1st US citizen in space (1961) John Glenn was the 1st US citizen to orbit the Earth. Shepard's Freedom 7 flight lasted 15 m 28s. John Glenn’s ride into space was a total of 4 hours, 55 minutes, and 23 seconds.

Project Gemini Goal: Teams of two astronauts in the same spacecraft meet up & connect with another spacecraft. The Gemini Program was a step between Project Mercury and the Apollo Program, and had four objectives: 1) To subject astronauts to long duration flights 2) to develop methods of docking with and maneuvering other orbiting vehicles in space; 3) to perfect methods of reentry and landing the spacecraft 4) to gain additional information concerning the effects of weightlessness on crew members and to record the reactions of crew members during long duration flights.

Goal: Successfully land a person on the Moon.
Project Apollo Goal: Successfully land a person on the Moon. Apollo I: Destroyed on the launch pad when an electrical fire erupted in the cockpit, killing the 3 person crew.(1967) The hatches could not be opened, because of the pressure of the hot gasses inside the command module, which soon ruptured. Emergency evacuation was very complicated, and had never been done in a little as 90 seconds. Rescue efforts were unsuccessful. 27 men were treated for smoke inhalation, two were hospitalized.

Edward White, Gus Grissom, Roger Chaffee

Apollo XI: Neil Armstrong & Edwin “Buzz” Aldrin successfully land on & explore the Moon. (1969)
Just twenty seconds' worth of fuel remained when Apollo 11's lunar module landed on the moon. The footprints left by the Apollo astronauts will not erode since there is no wind or water on the Moon. The footprints should last at least 10 million years. Astronauts Neil Armstrong, left, Michael Collins, center, and Buzz Aldrin

+ It would take 135 days to drive by car (~70 mph) to the moon
The average desktop computer contains 5-10 times more computing power than was used to land a man on the moon.

Apollo XIII: An explosion occurred in one of the oxygen tanks two days into the mission.
The crew was unable to land on the Moon, but returned safely to Earth 4 days later. Left to right: Lovell, Swigert, Haise

Square peg in a round hole
Mission control during splash down

Apollo engineer Jerry Woodfill said when Apollo 13’s switches were activated for reentry, the interior would surely have burst into flame, were it not for the fireproofing done on the module because of Apollo 1. Condensed water droplets might have short-circuited panel switches, circuit breakers, and connector wiring. Woodfill said America might never have landed a man on the Moon without Apollo 1. If a fire had occurred on the way to the Moon, it might have ended the will to land men there. “Imagine the horror of the world at such an event,” said Woodfill, “hearing the crew’s painful cries from deep space, ‘We’ve got a fire in the spacecraft.’”

Using the Earth’s terminator to navigate the burn (Apollo 13) had only been tried once before in space. And coincidentally, the astronaut who used it was Jim Lovell, during his previous flight — Apollo 8 — which orbited the Moon in December of 1968.

Apollo XVII: The last mission to the Moon
Apollo XVII: The last mission to the Moon. The 1st geologist (scientist) explores the Moon. Kansas Cosmosphere & Space Center  1100 North Plum Street, Hutchinson, KS has the Hall of Space Museum which is one of only three museums in the world to display flown spacecraft from all three early-manned American space programs – Mercury (Liberty Bell 7), Gemini (Gemini 10) and Apollo (Apollo 13) Gene Cernan was the last man to step on the moon in 1972.

Total Solar Eclipse August 21, 2017