Post on 19-Jan-2016
transcript
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 EarthREMEMBER: 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)
Exploring the Moon
1950s to 1960s - probes
Neil Armstrong First man on the Moon – July 20, 1969
Six Apollo missions (1969-1972) 382 kg (842 lbs)
rocks
12 Americans have walked on the moon
The Moon’s Surface
No atmosphere No liquid water Extreme
temperatures Daytime = 130C
(265°F) Nighttime = -
190C (-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 (365.24 days), does not relate to the lunar year (354.37 days), or 12 lunar months of 29.53 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 full moonwaxing crescent
first quarterwaxing gibbous waning 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.
http://www.nasm.si.edu/apollo30th/moontheater/phasepage2.html
The revolution of the Moon around the Earth makes the Moon look as if it is changing shape in the
sky.
http://btc.montana.edu/ceres/html/birthdayphases.htm
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.
http://btc.montana.edu/ceres/html/birthdayphases.htm
http://www.niehs.nih.gov/kids/lunar/why_phases.gif
Naming the phases of the moon.
New MoonThe 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
http://www.nasm.si.edu/apollo30th/moontheater/phasepage4.html
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starchild.gsfc.nasa.gov/docs/StarChild/questions/phases.html
Moon at Perigee and ApogeeDistance: 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 1998. Copyright Antonio Cidadao.
http://aa.usno.navy.mil/faq/docs/moon_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
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.
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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).
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Photo of a Total Eclipse
http://sunearthday.nasa.gov/2006/multimedia/gal_008.php
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.
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Photos of an Annular Eclipse
http://sunearthday.nasa.gov/2006/multimedia/gal_010.php; 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 LunarEclipses 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
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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.
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Tides and the Moon
Name this phase!
Full MoonWhat time does this phase rise and set?
Name these features.
Name these features.
Craters
Maria
Does this image show us the near side or far side of the moon?
Far SideHow 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?
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?
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?
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.
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.
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.
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
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.