earth -moon scale and orbit - monelison middle...
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Earth -Moon Scale and Orbit
http://solarsystem.nasa.gov/multimedia/gallery/Earth_Moon.jpg
What’s the Moon like?
What do people see when they look at the Moon?
http://photojournal.jpl.nasa.gov/catalog/PIA00094
http://www.lpi.usra.edu/resources/mapcatalog/LandingSite/index.html
http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=1757
How Big is the Moon?
Moon Size
~ 1/4 width of Earth
Radius of 1080 miles
Gravity ~1/6 of Earth’s
http://grin.hq.nasa.gov/IMAGES/SMALL/GPN-2000-001444.jpg
Relative Size and Distance of Earth and Moon?
http://nix.ksc.nasa.gov/info;jsessionid=gfuzp418gewa?id=C-1979-00910&orgid=2
http://visibleearth.nasa.gov/view_rec.php?id=1624
Earth and Moon to Scale
If Earth were a basketball, then the Moon would be a tennis ball,
23.5 feet away
Moon Stats No light of its own!!
Moon Rotation Spins on axis (rotates) once every 27.3 days
Tilted ~1.5 degrees
(Earth = 23.5)
Moon’s Orbit Orbits (revolves around) Earth every 27.3 days
Elliptical orbit (not a perfect circle)
360,000 km 406,000 km 224,000 miles 252,000 miles
http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=442
The Near Side The Moon rotates in 27.3 days.
The Moon orbits Earth in 27.3 days.
Because the Moon rotates and revolves at the same rate, we only see one side
The NEAR side There is NO DARK SIDE There is a FAR side….
And the Backside!
The FAR side
http://photojournal.jpl.nasa.gov/catalog/PIA00304
Moon Stats Moon’s orbit around Earth is inclined about 5 degrees to Earth’s plane of orbit around the Sun
Ecliptic plane
Sun Earth Moon
Moon’s orbital plane
Image created by LPI staff
There are two types of eclipses: Solar and Lunar
The difference between the two eclipses is simply where the moon is placed in relationship to the Earth and the Sun.
A solar eclipse occurs when the Moon passes directly between the sun and Earth. The moon blocks our view of the sun.
Although the sun is much larger than the Moon, it is much farther away. This causes the sun and moon to appear to be about the same size when viewed from earth.
This can only happen when the Moon is in the new moon phase.
The next total solar eclipse for our area will be seen August 21, 2017.
A lunar eclipse occurs when the Moon passes through Earth’s shadow.
This can happen only at the time of a full moon – when the Moon is in the opposite direction from the sun
The next Lunar Eclipse that can be seen from here will happen on April 14th, 2014.
The basic causes of tides are the gravitational attraction among Earth, the Moon and the Sun.
Both Earth and the Moon experience differing gravitational forces. These unbalanced forces generate tidal bulges on opposite sides of the Earth. (Think of what happens to a drink as you go around a curve in the car.)
Even though the moon is much smaller than the sun, the tides caused by the moon are more than twice as high as the tides caused by the sun.
During spring tides (Moon is either full or new), high tides are higher than normal and low tides are lower than normal.
During neap tides (1st and 3rd quarter moons), high tides are lower than normal and low tides are higher than normal.
***Spring Tides are 3x’s higher than Neap Tides***
Moon phases occur because of the position of the moon relative to the earth and sun.
The moon doesn’t give off light so the phases are created by its reflection of the sun’s light.
Seasons are created by the tilt of the Earth’s axis.
As the Earth travels around the sun, the tilt of the axis causes different parts of the earth to face the sun at different times of the year.
When the northern hemisphere (axis) is pointed towards the sun, the northern hemisphere is in summer…thus, the southern hemisphere is in winter.
When the axis for the northern hemisphere is pointed away from the sun, the northern hemisphere is in winter and the southern hemisphere is in summer.
These are called Solstices. The Summer Solstice occurs on or about June 21st and the Winter Solstice occurs on or about December 21st.
When the axis is not pointed at the sun, we have the equinoxes. During the equinoxes, both hemispheres receive the same amount of sunlight.
The autumnal equinox occurs around September 21st and the spring equinox occurs around March 21st.
