Astronomy

Terrestrial Planets: Hard-Rocky Dense Inner Planets

Jovian Planets:

Giant Gassy

Low Density

Outer Planets

The Planets: Revolve around Sun & Rotation on their Axis

Solar System Formation

Planets & stars form from gas clouds called

Nebulas.

Under the force of gravity the gasses contract & ignite into a star.Left over debris sticks together to form proto-planets called planetesimals.

• Stars use Nuclear Fusion to uniting hydrogen elements together.

The reaction creates Helium and gives off heat and light . Heavy

elements are made as a star ages.

A stellar nursery where stars are formed.

Life cycle of a star on the H-R Diagram

The luminosity (brightness of a star) is dependent on its temperature• The higher the temperature the more luminous the star.

Our sun is a main sequence star.

Death of a Low Mass Star

•Low mass stars will burn up their hydrogen & swell into

a red giant. Eventually the crust on a red giant

collapses & implodes.

•The material in the crust is turned into a gas and a white

dwarf is left behind to burn out.

Death of a High Mass Star

•High Mass stars swell into super red giants when the

crust collapses an explosion occurs called a Super Nova.

•Left behind is a

oA Neutron Star

o Or a Black Hole will be left behind

Neutron Stars surrounded by nebula supernova gasses

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Our universe is filled with billions and billions of galaxies!

Elliptical galaxy M-80

Side View of a Spiral Galaxy

Red Giants and Blue stars within two spiral galaxies. Which is older?

Our solar system is inside of the Milky Way Galaxy.

You are here among billions and billions of other stars.

The Big BangTheory:

•Explains the origin of the universe.

• According to the big bang, the universe was created sometime between 15 billion and 20 billion years ago from a cosmic explosion that hurled matter in all directions.

Red Shift/ Moving Away

Light energy emitted by an object moving away is stretched or red shifted.

Blue Shift/Coming Closer

The light and energy emitted by an object moving toward an observer is squeezed and has a blue shift.

Our universe is expanding based on an observed red shift

Lunar Eclipse

Solar Eclipse

http://www.astro.wisc.edu/~dolan/java/MoonPhase.html

Phases are caused by the revolution of the moon around the earth.

Motions of Planets, Stars, and Constellations

1. Appear to rise in the east set in the west in the night sky.

The earth has a counter clockwise rotation on its axis and causes objects to appear to rise in the east.

2. Some Planets Exhibit Retrograde Motion

-Outer planets look like they are moving backwards

http://www.opencourse.info/astronomy/introduction/05.motion_planets/

Two Proofs for the Earths Rotation

1. Foucault’s Pendulum

2. Coriolis Effect

The path of a freely moving fluid or gas in the northern hemisphere under goes a right hand deflection.

• Ocean Currents ESRT pg. 4

• Winds ESRT pg. 14

Geocentric Model Ptolemy 2000 yrs ago

• Earth is the center of the solar system.

• The Sun and Planets revolve around the earth.

• Epicycles used to explain apparent diameter changes of the planets.

-Could not predict planetary motions.

-Does not explain terrestrial proofs

Heliocentric Model Copernicus 1543 “The Correct One”

•Sun is the center as the solar system.

•Terrestrial proofs are explained.

•A simpler, accurate and predictable model

• Did not explain apparent size and speed of planets.

Improvement to the Heliocentric Model by Kepler.

• The planets move in elliptical orbits.• The orbital speed is greater when a

planet is near the sun.

Keplers 1st law.

Each planet revolves around the sun in an elliptical orbit.

• Measured by eccentricity or the out of roundness of a circle.

Eccentricity = Distance between Foci

Length of Major Axis

The Eccentricity of a Straight line is = 1

The Eccentricity of a Perfect Circle is = 0

SUN

Major Axis 20 cm

10 cm

Planet

Focus 2Focus 1

Kepler’s 2nd Law of Equal Areas

“A line from the sun to a planet will sweep across equal areas in equal time”

Aphelion

Perihelion

Planets Orbit

X Y

http://home.cvc.org/science/kepler.htm

http://www.astro.uiuc.edu/projects/data/KeplersLaws/

Keplers 3rd Law

• The greater the distance a planet is from the sun the slower its average speed and the longer its revolution.

Gravitational Force and Energy in Space

What keeps the universe from flying apart!• Newton's Law of Gravitation.

1. A force of attraction exists between two objects & depends on 3 factors.

1 Mass of planet 1 2 Mass of planet 2 3 The distance

between the 2

Elements can be identified by the electromagnetic energy they radiate using emission spectrum lines.

Argon

http://home.achilles.net/~jtalbot/data/elements/

Helium

Hydrogenhttp://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/

Using Your ESRT pg. 14 & the electromagnetic spectrum chart answer the following.

1. Convert the following scientific notation into a decimal. To convert, write a “0. then add as many zero’s as the exponent calls for minus one zero and add the whole number last.

For Example, 1*10-3 = .001

2. Next To each decimal using your ESRT pg. 14 name the electromagnetic wave.

Decimal Equivalent Name of Electromagnetic Wave

1*10-8 _________________, ___________________1*10-5 _________________, ___________________1*10-3 ________________, ___________________1*10-1 ________________, ___________________1*10 0 _________________, ___________________1*10 1 _________________, ___________________

3. Write the range of scientific notation for the following

forms of visible light and convert them to a decimal equivalent.

Scientific Notation Decimal Equivalent

• Violet _____________, ________________• Blue _____________, ________________• Green _____________, ________________ • Yellow _____________, ________________• Orange _____________, ________________• Red _____________, ________________

4. What type of electromagnetic energy has the smallest wavelength, which has the largest?