Set up for Cornell notes

What is the Moon?  A natural satellite  One of more than 96 moons in our Solar System  The only moon of the planet Earth  REMEMBER: planets orbit suns. Moons orbit planets.

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)

Birth of the Moon  “Born” 4-5 billion years ago  Formed from impact of Mars- sized “planetesimal” on Earth  Debris from both objects melted together to form the Moon

Exploring the Moon  1950s to 1960s - probes  Neil Armstrong First man on the Moon – July 20, 1969  Six Apollo missions ( )  382 kg (842 lbs) rocks  12 Americans have walked on the moon

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

Lunar Features - Highlands  Mountains up to 7500 m (25,000 ft) tall  Rilles (trenchlike valleys)

Lunar Features - Craters  Up to 2500 km (1,553 miles) across  Most formed by meteorite impact on the Moon  Some formed by volcanic action inside the Moon

Lunar Features - Maria  Originally thought to be “seas” by early astronomers  Darkest parts of lunar landscape  Filled by lava after crash of huge meteorites on lunar surface 3-4 billion years ago  Mostly basalt rock

Maria Craters Does this photo show us a limb or terminator line?

Movements of the Moon  Revolution – Moon orbits the Earth every 271/3 days  The moon rises in the east and sets in the west  The moon rises and sets 50 minutes later each day  Rotation – Moon turns on its axis every 27 days  Same side of Moon always faces Earth

Far Side of the Moon  First seen by Luna 3 Russian space probe in 1959  Surface features different from near side  More craters  Very few Maria  Thicker crust

Humans are instinctively drawn to naturally recurring patterns, as their predictability seem to fulfil a deeply felt longing for logic and order within our chaotic and ever-changing universe. Away from the equator, the length of the day varies throughout the year, the beginning of seasons are not clearly definable, and astronomical processions are complex to follow. But for primitive people, the Moon displayed a relatively simple recurring cycle from a New to a Full Moon. A lunar calendar It comes as little surprise that most early calendars were based on lunar phases. The Jewish lunar calendar

Unfortunately, the orbital period of the Earth around the Sun, or the length of the astronomical year ( days), does not relate to the lunar year ( days), or 12 lunar months of days. This is why the lunar calendar is only kept nowadays for folkloristic (e.g. astrology) or religious (e.g. the Islamic calendar or Hijri) recurrences. So every few years the lunar calendar has to be readjusted, usually adding an extra 13th month, to coincide with the solar year. new moon full moon waxing crescent first quarter waxing gibbouswaning gibbouslast quarter waning crescent AphelionPerihelion Moon 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”

Half of the Moon is always lit up by the sun. As the Moon orbits the Earth, we see different parts of the lighted area.

The revolution of the Moon around the Earth makes the Moon look as if it is changing shape in the sky.

This is caused by the different angles from which we see the lighted part of the Moon's surface. These are called " phases " of the Moon.

lunar/why_phases.gif

Naming the phases of the moon.

New Moon The lighted side of the Moon faces away from the Earth. This means that the Sun, Earth, and Moon are almost in a straight line, with the Moon in between the Sun and the Earth. The Moon that we see looks very dark

Full Moon The lighted side of the Moon faces the Earth. This means that the Earth, Sun, and Moon are nearly in a straight line, with the Earth in the middle. The Moon that we see is very bright from the sunlight reflecting off it.

Waxing & Waning

30 starchild.gsfc.nasa.gov/docs/StarChild/questions/phases.html

Moon at Perigee and Apogee Distance: 359,861 km Distance: 405,948 km

Moon Movie The movie is an animated GIF created by Antonio Cidadao from a sequence of still images taken during March and April Copyright Antonio Cidadao.Antonio Cidadao on_phases.html

The Earth, Sun & Moon  In groups of 3 we are going to act out the movement of the Earth and Moon.  1 person is the Sun  1 person is the Earth  1 person is the Moon  Show how the Earth moves and how the moon moves

Model 1: Acting out the Phases of the Moon

Recording your results: Worksheet When the Sun, Moon and Earth are in these positions the moon looks like this from Earth. (Shade in this circle to show the shadow on the moon) This phase of the moon is called a Full moon

Eclipses

 Celestial bodies are always “eclipsing” or moving in front of each other.  Eclipses occur at predictable intervals.  Other names include: Transits and Occultations.  Usually we are talking about the sun, moon, and earth

Moon's shadow on Earth taken by French cosmonaut Jean-Pierre Haigneré aboard the Mir

Lunar Eclipses  Lunar Eclipse- When the Earth casts a shadow on the moon, causing the moon to go dark. Earth comes between the Sun and the Moon and casts a shadow on the Moon (Full Moon)

 Umbra – The dark inner portion of the shadow cone.  Penumbra – the lighter outer portion of the shadow.

Types of Lunar Eclipses  Total Lunar Eclipse – when the Moon passes completely into the Umbra, or total shadow of the Earth.  Partial Lunar Eclipse – Occur when the Moon does not fully move into the Umbra.  Penumbral Lunar Eclipse – When the moon passes only through the penumbra, or partial shadow. They are barely visible.

Total Lunar Eclipse – when the Moon passes completely into the Umbra, or total shadow of the Earth.

45 Why is the Moon red during an eclipse?  The Earth’s atmosphere filters some sunlight and allows it to reach the Moon’s surface  The blue light is removed—scattered down to make a blue sky over those in daytime  Remaining light is red or orange  Some of this remaining light is bent or refracted so that a small fraction of it reaches the Moon  Exact appearance depends on dust and clouds in the Earth’s atmosphere

Partial Lunar Eclipse – Occur when the Moon does not fully move into the Umbra

Penumbral Lunar Eclipse – When the moon passes only through the penumbra, or partial shadow. They are barely visible.

 Solar Eclipse- When the Moon casts a shadow on the Earth, causing the sun to go dark. The Moon comes between the Sun and Earth and casts a shadow on part of Earth (New Moon)

Types of Solar Eclipses  Total Solar Eclipse – can only occur if you are at the exact spot within the moon’s umbra (which isn’t very big).  Partial Solar Eclipse – Visible is you are in the penumbra of the shadow. Only some of the moon will be shadowed.  Annular Eclipse – occurs when the moon is farthest from the Earth in its orbit. This makes the moon look smaller, so during the eclipse you see an outer ring of light from the Sun.

Total Solar Eclipse – can only occur if you are at the exact spot within the moon’s umbra (which isn’t very big).

52 Photo of a Total Eclipse

Partial Solar Eclipse – Visible if you are in the penumbra of the shadow. Only some of the moon will be shadowed.

Annular Eclipse – occurs when the moon is farthest from the Earth in its orbit. This makes the moon look smaller, so during the eclipse you see an outer ring of light from the Sun.

55 Photos of an Annular Eclipse photos taken by Fred Espenak

How often do Eclipses Happen?  That depends!! Lunar Eclipses happen more often than Solar Eclipses.  Why? Well everyone who is experiencing nighttime during a lunar eclipse can see it.  But you have to be at the exact spot on Earth to see a Solar Eclipse.  The spot on Earth is so small, that the same place only sees a Solar Eclipse every 350 years!!

Why Don’t We See Lunar Eclipses More Often?  Well, lunar eclipses don’t happen everyday because the Moon’s orbit is tilted. So, during most months, the Moon is above or below the Earth.

 Syzygy- The times where the Moon, the Earth, and the Sun line up perfectly for an eclipse.

Tides and Review

But the Moon does have a real physical impact on our lives, for instance through its gravity pull (tidal cycles) and, especially on a full Moon, its reflected nocturnal illumination. Back to the real world Some aspects of animal life are also governed by the monthly lunar cycle, such as when eggs hatch in many species including tortoises and butterflies, or guiding bird migrations. ©2009 Mike Salway ©2008 HowStuffWorks Full Moon moonlight Nocturnal bird migration

62 Tides  The Moon’s gravity tugs on the Earth.  It pulls the most on the part of Earth closest, which raises the atmosphere, the oceans, and even the rocks (a little)  It pulls the least on the part of Earth that’s farthest, which allows the oceans and atmosphere to be further from the Moon (and higher)  The Sun’s gravity does the same thing, but to a lesser extent

When the moon is new or full, the gravitational forces of the sun and moon are pulling at the same side of the earth. (See the diagram below.) This occurrence creates the extra large "spring" tides. When the moon is at first and third quarter, the gravitational forces of the sun and moon are pulling at 90 degrees from each other. (see the diagram below.) This occurrence yeilds little net tides called neap tides.

64 Tides and the Moon

Name this phase! Full Moon What time does this phase rise and set?

Name these features. Craters Maria

Does this image show us the near side or far side of the moon? Far Side How can you tell?

Name this phase! First Quarter

Name this phase! Waxing Crescent

Does this image show the near side or the far side of the moon? Near Side

Name this phase! Waning Gibbous

Name this phase! Third Quarter

From what direction does the moon rise? The East

Name this phase! Waxing Gibbous

Name this phase! Waning Crescent

What might be happening in this image? Lunar Eclipse

True or False: The Far Side and the Dark Side of the moon are the same thing. False!

Name this phase! Full Moon

Name this phase! New Moon

Does the moon rise or set in the west? It sets in the west.

Name this phase! Waning Gibbous

Name this phase! Waning Crescent

Name this phase! Waning Gibbous

Why does a solar eclipse last for only a few minutes in any one location?

Because the Earth rotates, it will take only a few minutes to move out of the Moon's shadow.

Why can't you see a new moon?

The lighted half of the Moon is facing the Sun, not Earth.

When do the Sun's rays directly hit the Tropic of Cancer?

They directly hit the Tropic of Cancer during the summer solstice in the northern hemisphere (June 21 or 22).

Explain how a solar eclipse occurs.

A solar eclipse occurs when the Sun, Moon, and Earth align as Earth moves into the Moon's shadow.

Explain how a lunar eclipse occurs.

A lunar eclipse occurs when the Sun, Moon, and Earth align as the Moon moves into Earth's shadow.

Identify two properties of Earth that cause it to have changing seasons.

Identify two properties of the Earth that cause it to have changing seasons. Earth's tilted axis and Earth's revolution around the Sun are the properties that lead to Earth's changing seasons.

Explain the effect of each of the properties you named in the previous question.

During winter in Texas, Earth's tilt causes the Northern Hemisphere to be pointed away from the Sun. This means the Sun's rays are spread out over a large area. During summer, the Northern Hemisphere is pointed toward the Sun. Sunlight is less spread out, so areas get more solar energy and heat up. As Earth revolves around the Sun, the tilt of its axis does not change. So, when Earth gets to the other side of the Sun, it is tilted so that the Northern Hemisphere is away from the Sun.

Describe how the length of the days in the Northern Hemisphere changes with the four seasons

In the Northern Hemisphere, the longest days are in the summer months. The day length decreases through the fall. In winter, days are shortest. Day length increases during the spring. Earth's revolution around the Sun is a major cause of the changing day length.