Recent Changes

1) Distance between the earth and the sun is 150 million km.
b) light year= 9.5 x 10 km/ yr distance that a ray of light travels in one year.
Properties of Stars***Stars*
Size- range from the smaller then the earth to 2000 x the diameter of the sun.
Density- differ greatly
Luminosity- true brightness of a star depends only upon the size and temperature of a star.
Absolute Magnitude- expresses luminosity of stars as if they were seen from the same distance.
OF A STAR***STAR*
Stars form from dense clouds of gas and dust.
An outside force triggers the attraction of gravity causing particles to move toward one each other.
Contraction continues protostars become hotter and brighter.
The center becomes so hot fusion begins (Hydrogen Nuclei unit to form helium)
RedgiantsRed giants and SupergiantsSuper giants
Star loses stability.
The star gets so hot it causes the outer layers to expand, enlarging its surface area.
White dwarfs
Most of the fusion is used up.
pressure of tehthe core can
Glows faintly as it continues to cool.
Supernova
We belong to the milky way galaxy.
Spiral- central lens shape and spiral arms which usually contain millions of stars as well as dust and gas.
Big Bang Hypothesis
Universe was packed into one dense sphere of hydrogen.
15 billion years ago the mass exploded forming an expanding cloud.
Cloud parts condensed into galaxies.

b) Formula- distance between foci = eccentricity
.....................length of major axis...........................
5) THE PLANET AND THE SOLAR SYSTEM
-Terrestrial (Inner) Planets
a) mercury, venus, earth, and mars.
b) consist of a rocky crusst, a dense mantle layer, and a very dense core.
c) average density is above waterr
d) iron, silicon, oxygen, and other heavy materials.
-The asteroids that orbit between mars and jupiter divide the two groups.
-Jovian (Outer) Planets
a) a huge gaseous, and much less dense
b) hydrogen and helium
c) have ring systems
-centered around the planets equator
-Meteoroids- a rock or an ice fragment traveling in space.
-Meter- the light made by a meteoroid as traveling in space.
-Meteorite- part of a large meteorite that survives its trip through the atmosphere and strikes earth's surface.
a) 93 percent are stone
b) iron 85 to 95%. the rest is nickel.
c) stony- iron (rare mixturee of stone and iron)
7. the most abundant source of meteorites is in the arctic ice cap.
STARS AND GALAXIES
1) Distance between the earth and the sun is 150 million km.
b) light year= 9.5 x 10 km/ yr distance that a ray of light travels in one year.
Physical Properties of Stars***
Size- range from the smaller then the earth to 2000 x the diameter of the sun.
Density- differ greatly
Mass- the most stars are fairly close to the sun.
Color- depends on the surface temperaturee
Red- Cooler
Blue- Hotter
Elements- contain mainly helium
Brightness- apparent magnitude how bright a star appears to an observer on the earth.
Luminosity- true brightness of a star depends only upon the size and temperature of a star.
Absolute Magnitude- expresses luminosity of stars as if they were seen from the same distance.
ORIGIN OF A STAR***
Stars form from dense clouds of gas and dust.
An outside force triggers the attraction of gravity causing particles to move toward one each other.
Temperature increases as the area contracts.
If the cloud is large enough parts of it will start to glow.
---Protostars- large glowing cloud sections.
Contraction continues protostars become hotter and brighter.
The center becomes so hot fusion begins (Hydrogen Nuclei unit to form helium)
Redgiants and Supergiants
Star loses stability.
The star gets so hot it causes the outer layers to expand, enlarging its surface area.
The star radiates more light and appears brighter.
White dwarfs
Most of the fusion is used up.
Temperature and pressure of teh core can no longer support the weight of it's outside layers.
Glows faintly as it continues to cool.
Supernova
As the star core cools it begins to collapse.
Pressure and temperature rise dramatically.
The star explodes violently.
Black Holes
Gravitational forces are so powerful that even light can not escape.
Galaxy- a group of millions or billions of stars held together by gravity.
We belong to the milky way galaxy.
Spiral- central lens shape and spiral arms which usually contain millions of stars as well as dust and gas.

This page has all the great things I made in social studies class.
Here is my iMovie on the Assyrians.
{islamic achieve.notebook}
{arabian empire.notebook}
{spread of islam.notebook}
{riseofislam.notebook}
{five pillars.notebook}JEOPARDY*
{JEPORDY}

Shortest daylight of the year in the northern hemisphere.
{http://inlinethumb12.webshots.com/44299/2704330540104391629S600x600Q85.jpg} http://inlinethumb12.webshots.com/44299/2704330540104391629S600x600Q85.jpg
EARTH'S ORBIT
1) Parallelism of earth's axis- Every position of earth's axis in its orbit is parallel.
2) Earth's distance to the sun.
-@ Perihelion- 147,600,000 KM
-@ Aphelion- 152, 400,000 KM
3) Kepler's Laws
a) Planets travel in elliptical orbits. Therefor they will be at different distances from the sun throughout there revolution.
b) The equal area law- States that each planet moves around the sun in such a way that an imaginary line joining the planet to the sun will sweep over equal areas of space in equal areas of time.
c) The harmonic law- the farther the planet is from the sun, the longer its period of revolution.
4) Elliptical Eccentricity
a) Eccentricity- degree of the "out of roundness" of the ellipse.
b) Formula- distance between foci = eccentricity
.....................length of major axis...........................

A slightly elliptical orbit around the sun (counter clockwise)
365.25 days for one revolution.
Evidence-
seasonal change of the constellations the solar diameter varies in a cyclic pattern.
PERIHELION- sun is the largest occurs in the NH winter ( shortest distance between the earth and the sun)
APHELION- smallest occurs in the NH summer (largest distance between the earth and the sun)
Seasons
The earths tilt is= 23.5
Parallelism of the earths axis- The earths axis remains parallel throughout its revolution around the sun
Local moon- when the sun reaches its maximum altitude
Equinox- the sun is in the zenith position at the equator (March 21st and Sept. 23rd.)
12 hours of both daylight and darkness.
Summer Solstice- the sun is in the zenith position at the tropic of cancer (June 21st)
Longest daylight of the year in the northern hemisphere.
Winter Solstice- the sun is in the zenith position at the tropic of Capricorn (Dec. 21st)
Shortest daylight of the year in the northern hemisphere.
{http://inlinethumb12.webshots.com/44299/2704330540104391629S600x600Q85.jpg} http://inlinethumb12.webshots.com/44299/2704330540104391629S600x600Q85.jpg

Solar System Models
Geocentric
Earth centered system developed by ptolemy.
Was accepted until the 1960's.
Heliocentric
Sun centered system developed by Copernicus.
Modern understanding of the structure of the universe.
Celestial Objects- Objects observed in the sky during the day or night. (Planets, sun, moon, stars..)
Constellation- a group of stars that make an identifiable pattern in the sky.
{http://www.allthesky.com/various/preview/umaumim-p.jpg} http://www.allthesky.com/various/preview/umaumim-p.jpg
ROTATION
A spinning about the north and south axis.
Evidence: The apparent daily counter clockwise motion of celestial abjects around polaris (northstar) is because of earth's rotation towards the est (rate=15 degrees per hour)
Solar Day- the amount of time required for the earth to rotate from one noon to the next 15 degrees x 24 hours = 360 degrees.
Coriolis Effect
Horizontal deflection undergone by all moving materials on the earth's surface.
Northern hemisphere- deflected to the right (clockwise)
Southern Hemisphere- deflected to the left (counter- clockwise)
Foucault Pendulum
An experiment to demonstrate the rotation of the earth.
REVOLUTION
A slightly elliptical orbit around the sun (counter clockwise)
365.25 days for one revolution.

As soon as the front passes the temperature will decrease and the wind speed may rise. {http://z.about.com/d/weather/1/6/N/-/-/-/coldfront.png} http://z.about.com/d/weather/1/6/N/-/-/-/coldfront.png
{http://www.cbs6albany.com/images/research/Cold_Schematic.JPG} http://www.cbs6albany.com/images/research/Cold_Schematic.JPG
WARM FRONT
Warm air is advancing and replacing cold air.
Warm fronts move slower; warm are moves up a gentle frontal surface.
Warm air may travel 1000 km before rising 2 or 3 km.
First cirrus and cirrostratus clouds form and then there are altostratus clouds. Finally, steadt rain falls form nimbostratus clouds.
Precipitation can occur for 225-275 miles ahead of where the front touches the ground.
Warm fronts travel at speeds between 20-25 MPH.
Warmer temperatures follow the passing warm front. {https://secure.ucompass.com/educator/temp/guest/meteo1/images/warmfront.gif} https://secure.ucompass.com/educator/temp/guest/meteo1/images/warmfront.gif
OCCLUDED FRONT
A cold front is advancing and combining with a warm front.
Occluded fronts move the slowest of all (20 MPH)
The fronts are associated with cirrus and stratus clouds in front of the nimbostratus and cumulonimbus clouds.
Precipitation occurs for about 400 miles, most of which is in front of the frontal boundary.
Cool air is in front, as warm air is force up by the cold air which follows the passing occluded front.

The wind is deflected by the earth's rotation, called the coriolus effect.
{http://mynasadata.larc.nasa.gov/images/AtmosphCirc2.png} http://mynasadata.larc.nasa.gov/images/AtmosphCirc2.png
Air Masses
An air mass is a huge section of the lower troposphere that has the same kind of weather throughout.
The best source regions for air masses.
Air masses have two characteristics.
Temperature depends on weather if comes from the tropics or polar regions.
The HUMIDITY OF THE AIR MASS depends on whether it comes from land or sea.
Air masses are named from their source region.
C-continental (dry)
M-maritime (moist)
T-tropical
P-polar
A-arctic
{http://www.islandnet.com/%7Esee/weather/graphics/photos/naairmass2.jpg} http://www.islandnet.com/~see/weather/graphics/photos/naairmass2.jpg
Fronts are the boundaries between air masses are called fronts.
Cold Front- When cold air is advancing and replacing warm air.
Cold fronts are steeper and move faster than warm fronts.
The air rises upward rapidly forming cumulonimbus.
Heavy precipitation and thunderstorms which start and end quickly, are associated with cold fronts.
Precipitation covers 75-100 miles and occurs both BEFORE and AFTER a cold front passes at the surface.
Cold fronts travel at speeds between 25-30 MPH.
As soon as the front passes the temperature will decrease and the wind speed may rise. {http://z.about.com/d/weather/1/6/N/-/-/-/coldfront.png} http://z.about.com/d/weather/1/6/N/-/-/-/coldfront.png
{http://www.cbs6albany.com/images/research/Cold_Schematic.JPG} http://www.cbs6albany.com/images/research/Cold_Schematic.JPG

Rising barometer- greater pressure usually means cooler drier weather (sinking air)
Falling barometer- less pressure because the air i warm and moist and rises. This can be a sign of precipitation.
WIND
The horizontal movement of air from areas of high air pressure to areas of low air pressure.
The closer the spacing between isobars the stronger the winds.
Winds blow across isobars, from high to low air pressure.
{http://www.windfinder.com/grafiken/isobars/isobars_central_europe_1.gif} http://www.windfinder.com/grafiken/isobars/isobars_central_europe_1.gif
Global Wind Belts
Wind flowing from high pressure at the poles to low pressure at the equator.
The wind is deflected by the earth's rotation, called the coriolus effect.
{http://mynasadata.larc.nasa.gov/images/AtmosphCirc2.png} http://mynasadata.larc.nasa.gov/images/AtmosphCirc2.png