Solar System Notes
Solar System - An area that normally has one
star with planets, moons, asteroids and
comets orbiting the star. Our solar system
has 8 planets, dwarf planets, hundreds of
moons, countless asteroids and comets
Solar System Formation
1. Was a giant Nebula (cloud of gas and
dust)
2. Nearby explosion caused it to start
spinning
3. Most of the stuff pulled to center (the
sun)
4. Remaining stuff continued spinning
around sun – planets, comet, asteroids
The Order of the Planets
► 1.
► 2.
► 3.
► 4.
► 5.
► 6.
► 7.
► 8.
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
1. My
2. Very
3. Educated
4. Mother
5. Just
6. Served
7. Us
8. Nachos
Compare the size of the Sun
to all 8 Planets!
Compare the sizes of the Terrestrial
Planets:
Mercury:
► Closest
to the Sun
► Shortest Revolution
► Terrestrial Planet –Rocky Surface
► Inner Planet
► No Moons
► 1 day = 58 Earth days
► 1 year = 88 Earth days – shortest year
Venus:
► Close
in size, mass and density to Earth
► “Earth’s Twin”
► Hottest Average Temp.
► No Moon
► Retrograde Rotation – Spins backwards
► Inner planet
► Terrestrial Planet
► 1 day = 243 days – longest day – longer than year
► 1 year = 224 days
Earth:
►1
moon (Luna)
► Has liquid water
► Has the only known life
► Inner planet
► Terrestrial planet
► Revolution = 365.25 days
► Rotation = 24 hours
► Prograde Rotation
Mars:
►2
Moons
► Thin Atmosphere
► The “Red Planet”
► Smaller than Earth
► Terrestrial planet (inner planet)
► 1 day = 24.5 hours
► 1 year = 687 days
Compare the sizes of the Gas Giants
Jupiter
► Largest
Planet
► Made mostly of H and He
► Many moons (about 66)
► Has a red spot (1.5 X the diameter of Earth)
► Gas Giant – No Solid Surface
► Has a few rings.
► 1 day = 10 hours – shortest day
► 1 year = 12 Earth years
Saturn:
► Made
mostly of H and He
► Many moons (about 62)
► Less dense than water would float in a tub.
► Largest rings
► Gas Giant – no Solid surface
► 1 day = 10.5 hours
► 1 year = 29.5 years
Uranus:
► Much
smaller than Jupiter and Saturn
► Tilted at a 90 degree angle
► Has many moons (27)
► Retrograde rotation – spins backwards
► Gas Giant – No Solid Surface
► Has Rings
► 1 day = 18 hours
► 1 year = 84 years
Neptune:
► Much
smaller than Jupiter and Saturn
► Many moons (13)
► Gas Giant – No Solid Surface
► Has a few rings
► 1 day = 19 hours
► 1 year = 168.8 years – longest year
Pluto (No longer a “planet”)
► Dwarf
Planet
► 1 moon which is more than half the size of
Pluto (they orbit around each other).
► Orbit is so elliptical that it’s path is inside
Neptune’s for 20 years
► It just became last again in 2005.
A dwarf planet is a celestial body that:
1. Orbits the sun.
2. Has enough mass to assume a nearly round shape.
3. Has not cleared the neighborhood around its orbit.
4. Is not a moon.
The main distinction between a dwarf planet and a planet is that planets have
cleared their path around the sun while dwarf planets tend to orbit in elliptical
paths that cross each other.
Ceres is in Asteroid Belt between Mars and Jupiter.
“Plutoids” are Dwarf Planets that orbit out beyond
Pluto.
Smaller Objects
Asteroids - Rocky, metallic objects that orbit the
sun, normally in an orbit similar to a planet
Comet – Made of ice and rock. It’s orbit takes it
close to the sun and then very far. As it gets
close, comet starts to melt creating a tail
Not to Scale
Asteroid Belt
Smaller Objects
Meteor - A piece of rock from space that enters
Earth’s atmosphere and burns, creating a bright
streak of light across the sky. (shooting star)
Meteoroid – A small, broken up pieces of asteroids
or comets.
Meteorite – A piece of rock that lands on the Earth.