Solar System NotesTest – Thursday, 2/20
Textbook & Online Resources:Chapter 4 – Lesson 1: Introducing the Solar SystemChapter 4 – Lesson 3: The Inner PlanetsChapter 4 – Lesson 4: The Outer PlanetsChapter 4 – Lesson 6: Models of our Solar System
• Early ideas about the solar system followed a geocentric model.
• This means that the Earth is in the center of the solar system, and the Sun and other planets revolve around the Earth.
• Ancient Greeks – Ptolmey - (140 AD)
Geo = Earth
• The model of the solar system that scientists use NOW is the heliocentric model.
• This means that the Sun is in the center of the solar system, and the Earth and other planets revolve around the Sun.
Helio = Sun
Copernicus – 1543……….proved by Galileo -1610
It took a long time for people to accept the heliocentric model, because they thought the Earth must be the “center of the universe.”
Add this to your notes…
• Day = 1 rotation (1 spin on axis)
• Year = 1 revolution (1 trip around the sun)
The Inner Planets
• Small & Dense• Terrestrial = Made
of rock & metallic minerals
• All except Mercury have atmospheres
IMPORTANT!!!
• You do NOT need to memorize all of the facts and figures about the planets!!!
• Just know how they compare to Earth…– Bigger or smaller– Hotter or colder– Longer year or shorter year
MercuryDiameter = 4,879 km Gravity = 0.37 X EarthDistance from Sun = 0.39 AUAve. Temp. = -170o to 430o C # of Moons = 0Day = 58.9 Days Year = 88 Days
Mercury
• No atmosphere (causes extreme temps.)• Rocky surface w/craters• About the size of Earth’s moon
VenusDiameter = 12,104 km Gravity = 0.90 X EarthDistance from Sun = 0.72 AUAve. Temp. = 460o C # of Moons = 0Day = 244 Days Year = 224.7 Days
Venus• Thick atmosphere, made of carbon dioxide (CO2)
with clouds of sulfuric acid.• HOTTEST planet - Traps heat by the greenhouse
effect• Surface has more than 10,000 volcanoes• Rotates in the opposite direction of other planets
EarthDiameter = 12,756 km Gravity = 1 X EarthDistance from Sun = 1 AUAve. Temp. = Just Right Average 7.2o C
(Record Temps: -89 to 70o C)# of Moons = 1Day = 24 hours Year = 365.25 days
Earth
• 70 % of surface is liquid water• “Goldilocks Zone” b/c temp. is just right• Atmosphere is 20% oxygen• Greenhouse effect keeps us warm
Earth’s Moon
Diameter = 3,476 km Gravity = 0.16 X EarthDistance from Sun = about 1 AUAve. Temp. = -170 to 130o C
Earth’s Moon• The surface has…
– Maria - hardened rock from lava flows 3-4 billion years ago
– Craters - caused by impacts of meteors
– http://apod.nasa.gov/apod/ap120320.html
Mars
Diameter = 6,794 km Gravity = .37 X EarthDistance from Sun = 1.52 AUAve. Temp. = -140 to 20o C # of Moons = 2Day = 1.03 days Year = 1.88 years
Mars• No liquid water, but does
have ice• Atmosphere is 95% carbon
dioxide (CO2)
• Red color due to iron-rich rocks rusting
Fun Facts:• Has the largest volcano, 3X’s larger than
Mt. Everest• May have microscopic life (methane in
atmosphere)• Had liquid water in the past
The Outer Planets
• Called “Gas Giants” b/c much larger & made of gas… but inside is liquid b/c of pressure.
• No solid surface• Have rings made of rock
and ice• Have many moons
JupiterDiameter = 142,984 km Gravity = 2.36 X EarthDistance from Sun = 5.20 AUAve. Temp. = -145o C (surface) # of Moons = 63Day = 9.9 hours Year = 11.9 years
Jupiter • Largest planet• Atmosphere
made of hydrogen (H) and helium (He)
• Great Red Spot = hurricane larger than Earth
• May have rocky core and liquid mantle
SaturnDiameter = 120,536 km Gravity = 1.06 X EarthDistance from Sun = 9.54 AUAve. Temp. = -175o C (surface) # of Moons = 61Day = 10.7 hours Year = 29.5 years
Saturn• Atmosphere made of hydrogen (H) and helium (He).• Has wide, thin rings made of ice and rock that orbit
around Saturn
Saturn in Infrared LightSaturn’s Rings in UV Light
Uranus (YOOR uh nus)Diameter = 51,118 km Gravity = 0.88 X EarthDistance from Sun = 19.2 AUAve. Temp. = -224o C (surface) # of Moons = 27Day = 17.2 hours Year = 83.8 years
Uranus
• Blue-green color from methane in atmosphere
• Rotates vertically (rolling instead of spinning)
NeptuneDiameter = 49,528 km Gravity = 1.12 X EarthDistance from Sun = 30.07 AUAve. Temp. = -228 o C (surface) # of Moons = 13Day = 16.1 hours Year = 163.8 years
Rules of the Solar System
The closer a planet is to the Sun…– The shorter the year (revolution)– The hotter – Terrestrial (made of rock)– Smaller, less gravity, fewer moons
Rules of the Solar System
The farther a planet is from the Sun…– The longer the year (revolution)– The colder – Gas Giant– More mass, more gravity, more moons