A look at our nearest neighbor in Space! The Moon A look at our nearest neighbor in Space! Free powerpoints at http://www.worldofteaching.com

Myths about the Moon The Moon is made of cheese! There is a Man in the Moon.    The Moon and the Sun chase each other across the sky.  The Moon disappears during certain days of the month. There are men or other creatures living on the Moon.  The Moon was put in the sky by a person or animal.  The Moon is a living creature or a god.  The Moon controls how we act and how we feel.               During a full moon, some people turn into werewolves.  The Moon is pulled across the sky by a person, animal, or force.    

What is the Moon? A natural satellite One of more than 96 moons in our Solar System The only moon of the planet Earth

The Earth has 1 moon that revolves around the Earth. It takes 29.5 days for the Moon to orbit the Earth.

Location, location, location! About 384,000 km (240,000 miles) from Earth 3,468 km (2,155 miles) in diameter (about ¼ the size of Earth)

Moon Orbit Near Side Far Side The Revolution period around the earth – 29.5 days! The Rotation period is exactly the same! We always see the same side of the moon!

Moon’s orbit The orbit plane of the moon is tilted by ~5 degree with respect to the earth’s orbit around the sun.

It’s Just a Phase Moonlight is reflected sunlight Half the moon’s surface is always reflecting light From Earth we see different amounts of the Moon’s lit surface The amount seen is called a “phase”

As the moon moves (revolves) around the Earth, it looks like it has different shapes. The shape of the moon does not really change. It just changes its location in space.

Let’s take a closer look at the phases of the moon. During a new moon, the moon looks dark.

This is a waxing crescent. As the surface of the moon that we see gets bigger, we say that the moon is waxing. This is a waxing crescent.

This is a waxing quarter moon. When the moon is ¼ of the way around the earth, it is in its first quarter phase. We see it as half lit. This is a waxing quarter moon.

After the quarter moon, the moon is moving towards a full moon After the quarter moon, the moon is moving towards a full moon. We call this a waxing gibbous moon. Notice that the bright part of the moon is getting larger. That’s what we mean by “waxing.”

Now it’s time for a full moon Now it’s time for a full moon. The entire face of the moon that we are able to see shines during the full moon.

This is a waning gibbous moon. Following the full moon, the surface of the moon seems to be getting smaller. We call this a waning moon. This is a waning gibbous moon.

Now that the moon is ¾ of the way around the Earth, it seems to be half lit. We call this a waning quarter moon.

Before we get to the new moon, we see a sliver of moon shining up in the sky. This is a waning crescent.

One Month Later, 4 weeks since the last New Moon The New moon is when the moon looks dark.

Wax ON… Wane OFF… the DOC will help you… D – O - C

It takes the moon about 1 month (29 ½ days) to go through the phases Phases of the Moon It takes the moon about 1 month (29 ½ days) to go through the phases

The Moon’s Surface No atmosphere No liquid water Extreme temperatures Daytime = 130C (265°F) Nighttime = -190C (-310 F) 1/6 Earth’s gravity

Moon’s surface Highland Maria (sigular mare, ‘sea’ in Latin) Maria Crater Maria (sigular mare, ‘sea’ in Latin) Dark areas and were thought to be seas Cover 31% of the near side, but only 2% of the far side No water but vast pools of solidified lava that flowed into basins formed by comets/metors colliding Nomenclature Latin terms describing the weather and abstract concepts Smaller dark regions Lacus (Lake) Palus (marsh) Sinus" (bay)

Moon’s surface Highland Highland Maria Crater Lighter color regions, or called Terrae Many are impact basins’ outer rims In contrast to earth, no major lunar mountains were formed as a result of tectonic events Mountains and mountain ranges Different brightness of the highlands and maria is because they are composed of different rock types

Craters Daedalus, 93 km in diameter Formed when asteroids/comets hit the lunar surface Half a million craters with diameters larger than 1km Crater counting – to estimate the age of the lunar surface The largest crater is South Pole-Aitken basin, with 2,240 kms in diameter and 13 kms in depth Nomenclature: Large craters, deceased famous scientists, artists Small craters, common first names Daedalus, 93 km in diameter Proposed as a site for a large radio telescope

Known maria, highlads and craters

The End