Our solar system is one of over 500 known solar systems in the entire Milky Way Galaxy.

The solar system came into being about 4.5 billion years ago, when a cloud of interstellar gas and dust collapsed, resulting in a solar nebula, a swirling disc of material that collided to form the solar system. 

The solar system is located in the Milky Way's Orion  star cluster.

Only …15%……. of stars in the galaxy host planetary systems, and one of those stars is our own sun.

Revolving around the sun are ………8………… planets. The planets are divided into two categories, based on their composition, ………terrestrial………………. and ………jovian………….

Terrestrial planets including ………mercury………………., ……venus…………, ……earth………, and …mars…., are primarily made of ……rocky…………. material.

Their surfaces are ……solid…………., they …dont………. have …ring……... systems, they have very …few….. or …no.. moons, and they are relatively ……small………….

The smallest and closest to the sun is ……mercury…………………., which has the ……shortest………… ……orbit…. in the solar system at about …3……….. Earth months.

Venus is the ……hottest…………… planet, with temperatures of up to …867…. degrees Fahrenheit, due to an atmosphere of …CO₂………… ………...…………. and extensive …lava…….. flows.

Next to this world of fire is a world of water, …earth……….... The ……water…………. systems on this planet help create the only known environment in the universe capable of sustaining ……life…...

The last of the terrestrial planets, …mars…….., might have also supported life about 3.7 billion years ago,when the planet had a watery surface, and moist atmosphere.

Beyond the four Terrestrial planets of the inner solar system lie the Jovian planets of the …outer………. solar system.

The Jovian planets include …gas…… ………giants………. Jupiter and Saturn and …ice…… ………giants………. Uranus and Neptune.

The gas giants are predominantly made of ………helium…………….. and ……hydrogen……………….., and the ice giants also contain …rock…., …ice…..,  and a liquid mixture of ……water…… , ………methane……………. and ……ammonia………………...

All four Jovian planets have …multiple………………….. moons, sport …ring……... systems, have …no…… ……solid……….. surface, and are ………immense……………...

The largest Jovian is also the largest planet in the solar system, …jupiter…………………...

Nearby is …saturn………………….., the solar system's second largest planet. Its signature …rings…….. are wide enough to fit between Earth and the moon but are barely a ……km………………….. thick. `………uranus…………….. and ……neptune………………... The slightly bigger of these ice giants, Uranus, is famous for rotating on its …side…....

Next to Uranus is ………neptune…………….., the ……outermost………………….. planet in the solar system, and also one of the …coldest…………………..

Orbiting the Terrestrial planets is the ……asteroid belt……., a flat disc of rocky objects, full of remnants from the solar system's formation.

From microscopic …dust……... particles, to the largest known object, the dwarf planet, …ceres……….

Another …disc……. of space …debris……………. lies much further out, and orbits the Jovian planets, the icy …………Kuiper………….. Belt.

Apart from asteroids, the Kuiper Belt is also home to dwarf planets, such as …pluto………., and is the birthplace of many ……comets………….

Beyond the Kuiper Belt is the …oort……… …cloud……….., a vast, spherical collection of …icy…… ……debris………...

It is considered the …edge…. of the solar system since that is where the ……gravitational…………………….. and ……physical……………….. influences of the sun ……end…...….

Comets, Asteroids, and Meteors

Kepler’s Laws

Summarize Kepler’s laws of planetary motion. Include any equations or definitions that may be helpful.

1. Kepler’s First Law of Planetary Motion: the orbits of planetary bodies are ellipses with the sun at one of the two foci of the ellipse.

2. Kepler’s Second Law of Planetary Motion: states that if you were to draw a line from the sun to the orbiting body, the body would sweep out equal areas along the ellipse in equal amounts of time. This is easier to observe graphically. In the diagram, if the orbiting body moves from point 1 to point 2 in the same amount of time as it moves from point 3 to point 4, then areas A1 and A2 must also be equal.

3. Planets that are closer to the sun have smaller orbits and shorter periods. ]

P₁² = R₁³                                 P² = R³

P₂²    R³₂    

M

Perihelion distance is 1-e       aphelion distance is 1+e            

e = eccentricity

Practice: Calculate the orbital period of Venus given a distance of 0.72 AU. Calculate again if the orbital period of earth was reduced to 0.5 years

1.  P² = 0.72³        

P= 0.61 years                      

2. 0.5² = 1³

P₂²    0.72³

P₂ = 0.3 years

The Sun

Label the diagram of Sun. Include brief explanations of each region below

•  Corona: hot! (few million degrees), emits high energy radiation, earth's atmosphere absorbs the x-rays, but satellites can detect them

•  Chromosphere: 2500 km thick, thin reddish ring, dark features called filaments (prominences), spicules (massive jets of plasma) are visible 

•  Photosphere: most energy is white light, coolest regions of the sun, only a small fraction is plasma, thin compared to earth's atmosphere, sunspots have magnetic fields, solar interior bubbles, churning pattern called solar granulation

•  Convection zone: above radiation zone, convection occurs, 

•  Radiation zone: energy from atom to atom in the form of electromagnetic waves/radiation

•  Core: extremely hot dense gas, 15 million degrees, energy is produced, density allows for nuclear fusion

The Moon: Label the moon phases below

 Time to complete orbit: 27 days 

Time to complete rotation: 27 days

Define tidal locking: When an object's orbital period matches its rotational period. For example, the Moon. The moon takes 27 days to go around the Earth and 27 days to rotate once around its axis. This results in the same face of the Moon always facing the Earth.