Our Moon & Moon Our Moon & Moon ExplorationExplorationAstronomy 1

VocabularyVocabularyNew moonWaxing phaseFull MoonWaning phaseSolar eclipseLunar eclipseTides

CratersMariasHighlands

Moon FactsMoon FactsThere is no air, liquid

water or atmosphereTemperatures range

from 100°C to -170°CThere is little gravity

compared to the Earth

3,476 km in diameter (little less than the distance across the United States)

Origin of the MoonOrigin of the Moon Before the first manned

explorations of the moon there were several theories on the origin of the moon

1st: the moon was another smaller plane that was captured by Earth’s gravity

2nd: the moon was created by loose, left over material from when the Earth was forming

3rd: the moon was created by molten (liquid rock) material ejected from the Earth when the Earth was forming

Origin of the MoonOrigin of the Moon After the first mission

scientists gather data that led them to create the Impact Theory

The Impact Theory is just as it sounds – in the early development of the solar system there were a lot of collisions and explosions between all the debris

It is believed that at one time the Earth was much larger than it is now and was hit by a Mars-sized planet, causing a chunk to break off, creating the moon

Origin of the MoonOrigin of the Moon Over time both the

Earth and the moon were smoothed out to create the spheres we see today

They developed this theory because the lunar rocks that were gathered on the Apollo missions were no different than rocks you can find in the parking lot

Many of the hits the moon took as it formed can still be seen today – why?

Motions of the MoonMotions of the Moon The moon would be

considered a satellite because it revolves around the Earth

It takes approximately 27.3 days to make a complete trip around the Earth

The moon takes approximately 27.3 days to rotate on its axis

What does this mean? This also means that we

only see one side of the moon

Phases of the MoonPhases of the Moon The moon it self does

not give off any light – the only reason that we see the moon is because the light from the sun is reflecting off it

The different shapes of the moon you see at night are because the moon goes through phases as it revolves around the Earth and the sun is hitting it at different angles

Phases of the MoonPhases of the MoonWhat causes the

phases? The change in position of the moon relative to the sun and Earth is what causes the phases.

As the moon travels around the Earth, the sun hits different angles of the moon ◦ For example, if the moon is

angled towards Earth so only half is showing, then the sun will only hit the half we see

Phases of the MoonPhases of the Moon New moon: the lighted

sided of the moon is facing the sun, not Earth, and as a result the moon cannot be seen from Earth

Waxing phase: occurs after the new moon; the moon slowly begins to reappear in the sky, until it reaches a full moon◦ The Waxing Crescent is

when only a sliver of the moon is visible – occurs just after the new moon

◦ When one half of the moon is lit (1/4 of the total moon surface), the phase is called First Quarter

◦ When more than one half of the moon is lit (1/2 of the total moon surface), the phase is called Waxing Gibbous

Phases of the MoonPhases of the Moon Full Moon: the entire moon

is lit by the sun Waning Phase: occurs after

the full moon; slowly begins to disappear in the sky, until it reaches the New Moon◦ When more than one half

(1/2 of the surface) of the moon is showing, it is called the Waning Gibbous

◦ When one half (1/4 of surface) of the moon is showing, it is called the Third Quarter

◦ The Waning Crescent is when only a sliver of the moon is showing – just before the new moon

EclipsesEclipsesWhen the moon’s

shadow hits the Earth or the Earth’s shadow hits the moon an eclipse occurs

There are two types: a lunar and a solar

During a New Moon the moon is directly between the Earth and the sun – this occurs approximately once a month

EclipsesEclipsesSolar eclipses are

much more rare because only a few occur in a person’s lifetime

A solar eclipse occurs when the moon passes directly between the sun and the Earth – as a result you see a dark spot on the sun and the sky darkens until the moon, sun and Earth are no longer aligned

EclipsesEclipsesLunar eclipses are

still rare, but not as rare as a solar eclipse

A lunar eclipse occurs when the Earth passes between the sun and the moon – as a result the full moon will disappear in the sky until the moon, sun and Earth are no longer aligned

TidesTides Tides in the ocean occur

because of the attraction of gravity between the Earth and moon

Like the Earth revolving around the sun in a elliptical shape, the moon revolves around the Earth in an elliptical shape

High tides occur when the moon and Earth are closer together and the attraction is stronger

Low tide occurs when the moon and Earth and farther apart and the gravitational force is weaker

Studying the MoonStudying the Moon At the present time there

are no missions planned to return to the moon

However, there is a spacecraft that was placed in the lunar orbit to study the moon

This craft is called Clementine

Many pictures of the moon’s surface have been compiled, now the space craft is used to track cold objects that move through space (e.g. satellites, asteroids, war-heads, etc.)

Studying the MoonStudying the MoonClementine has given

scientists almost a complete map of the moon’s surface

A depression has been discovered that is almost 12km deep and 2500km wide – the largest in the solar system

There is also a large plateau that is almost always facing the sun

Studying the MoonStudying the Moon Features used to describe

the moon include: craters, highlands and Marias

Craters found depressions formed from high-speed meteoroids◦ These are evidence that the

moon is geologically dead Dark, flat areas are called

Marias – formed by ancient lava flows

Highlands light-colored areas surrounding the maria

Craters

Maria

Exploring the MoonExploring the Moon1950s to 1960s -

probesNeil Armstrong

First man on the Moon – July 20, 1969

Six Apollo missions (1969-1972)◦ 382 kg (842 lbs)

rocks12 Americans have

walked on the moon

Missions to the MoonMissions to the MoonBetween 1964-1972

over a dozen missions to the moon occurred – both manned and unmanned

Apollo 11 was the first manned mission that actually landed on the moon safely

From this mission we got the quote “One small step for man, one giant leap for man-kind.”

Missions to the MoonMissions to the Moon In later trips to the moon

astronauts were able to stay for days instead of hours, and even had a lunar buggy so they could travel around the moon’s surface

Astronauts also discovered much about the inside of the moon

They found that there are no plates, like on Earth, so the surface does not shift

The core of the moon has cooled almost completely, unlike the core of the Earth so the moon is geologically dead

Ice on the Moon?Ice on the Moon?

1994 – Clementine probe1998 – Lunar Prospector

Ice on the Moon?