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.
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.
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...........................
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)
Red giants and Super giants
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 the 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.
Big Bang Hypothesis
Universe was packed into one dense sphere of hydrogen.
15 billion years ago the mass exploded forming an expanding cloud.
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.
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.
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.
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...........................
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)
Red giants and Super giantsWhite dwarfs
- Most of the fusion is used up.
- Temperature and pressure of the 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 HolesGalaxy- a group of millions or billions of stars held together by gravity.
Big Bang Hypothesis