Download Inner and Outer Planets - Sonoma Valley High School

Planets of our solar system
formation of the solar system
• 4.6 billion years ago, the solar system was a
nebula, a cloud of dust and gas
• It began to rotate and flatten, with heavier
particles moving toward the center of the disc
the Nebular model
• Planetesmals grew
bigger and collected
more material.
• Radiation from the
new sun pushed
gases to the outer
regions, leaving rocky
planets closer in.
Cat’s eye nebula
Two categories of planets
•The planets closest to the
sun are the inner planets
• The inner planets are rocky
They include: Mercury, Venus,
Earth, & Mars
• The outer planets are
farther from the sun
– They have thick
atmospheres & rings
• Known as gas giants
– Includes: Jupiter,
Saturn, Uranus, &
Neptune
Mercury
• Closest planet to the sun
• No atmosphere
• Day temperatures go up to 670 K
(melts metal)
• Night temps go down to 103 K
• Spins slowly: 1 day = 58 Earth days
• Fast orbit: 1year = 87.6 Earth days
– (Kelvin scale: freezing point of water is
273 K, boiling point of water is 373 K)
Venus
• 105 million km from
sun
• same size as earth
• One day = 225 Earth
days
• One Year = 219 Earth
days
• Atmosphere of CO2,
sulfuric acid
• Temps 700 K, surface
pressure is 90 times
that of Earth
Earth
•
•
•
•
Only planet with liquid water on the surface
Hydrosphere supports and maintains life
Atmosphere shields radiation, burns up meteors
1 year = 365 days
1 day = 24 hours
Why Earth is called the “Goldilocks” planet.
Mars: the red planet
• Polar icecaps have frozen
water, CO2
• Largest volcano in solar
system
• Thin atmosphere mostly
CO2
• Year = 693.5 Earth days
• Day = 24.6 Earth hours
• 10% the size of Earth
• Temp. 144 – 300 K (cold)
• Has 2 moons
Asteroid Belt
• Objects 3km to 700
km diameter
• In the space between
Mars & Jupiter
• Some hit earth as
meteorites, seen as
“shooting stars”
Jupiter
• Largest planet – could
hold 1,300 Earths
• Red spot a hurricane
2X + the size of Earth
• 1 year = 12 Earth
years
• One day = 10 hours
• 50 moons (& counting)
How old would you be if you were
born on Jupiter?
Moons of Jupiter
Saturn
• Rings are tiny bits of
dust, rock, & ice
• 95 x the mass of the
Earth
• 1 year = 29 Earth years
• 1 day = 10.7 hours
• Has 53 moons
Moons of Saturn
Uranus
• Frozen methane gives a
blue-green color
• 14X mass of earth
• Axis is tilted 98 degrees
• Extreme seasons
• Has 27 moons
• 1 year = 84 Earth years
• 1 day = 17 hours
Why Uranus has extreme seasons.
Neptune
Photo by Voyager II
• Discovered because
of it’s gravitational pull
on Uranus
• Its magnetic field is
27x that of earth’s
• Has 13 moons
• 17X Earth’s mass
• 1 year = 165 Earth
years
• 1 day = 17 hours
Summary
Review
1.What is the
smallest
planet?
2.Which planet
has the longest
day?
3. Which planet
has the most
moons?