Long, long ago
in a galaxy
far, far away
(room 5-1),
a group of fifth graders
(that’s you!)
were learning about space…
Space
The Final Frontier
Part 1 – Planets in Our
Solar System
What is a solar system?
• A system of planets, moons, comets,
asteroids, dust, gases, and anything else
that orbit a star and are tied to its
gravitational force
• The sun (a yellow star) is the center of our
solar system
Previously in the study of space…
• Around 200 BC
– Aristarchus (Greek)
– Sun was the center
• Ptolemy
– Greece, early 100s
– The earth was the
center of the universe
• Copernicus
– Polish astronomer
– 1543
– The sun was the
center of the
solar system
– Planets revolved
in circles around
the sun
– Proved using mathematical data
• Modern Model
– Early 1600s
– Johannes Kepler
– Planets travel in elliptical (oval-shaped, like a
flattened circle) orbits around the sun
– Proven mathematically by Sir Isaac Newton
Modern Model of the Solar System
Planets
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AKA major planets
A body that revolves around the sun
Gravity keeps them in orbit
Shine because they reflect light from the
sun
• Mercury, Venus, Earth, Mars, Jupiter,
Saturn, Uranus, Neptune
– Many Very Entertaining Monkeys Just Stay
Up Nights
Planets continued
• Revolve around the sun (year)
• Rotate (spin) on an axis (day/night)
The Inner Planets
Mercury, Venus,
Earth, Mars
Mercury
• Closet planet to the sun
• Diameter (distance across): 3,000 miles
• Temperature: Between 800 degrees and
-280 degrees Fahrenheit (F)
• Distance from the sun: 36 million miles
• Length of day (in Earth time): 176 days
• Length of year (in Earth days): 88 days
• Natural satellites: 0
Mercury
Special characteristics:
– Smallest planet
– Moon-like surface
– Dry, hot, airless
(no atmosphere)
– Oldest surface
– Least explored
– Sun’s rays are 7 times as strong as they are on Earth
– Travels at a speed of 104,000 mph
– Named for the Roman god of trade and profit
Venus
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2nd planet
Diameter: 7,520 miles
Temperature: 864 degrees F
Distance from the sun: 67 million miles
Length of day: 243 days
Length of year: 225 days
Natural satellites: 0
Venus continued
• Special characteristics:
– Brightest object in morning and evening sky (outside
of moon)
– Clouds of sulfuric acid, hurricane force winds, and
lightning
– Heavy atmosphere – carbon dioxide, nitrogen
– One school day on Venus would last 4 months!
– Almost all features are named for extraordinary Earth
women
– Named for Roman goddess of love
– Spins backwards
Earth
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3rd planet
Diameter: 7,926 miles
Average temperature: 59 degrees F
Distance from the sun: 93 million miles
Length of day: 24 hours
Length of year: 365 days
Natural satellites: 1
Earth continued
• Special characteristics:
– 2/3 water, 1/3 land
– Only planet known to have living things
– Nitrogen and oxygen
• Oxygen rich environment
– Travels at a speed of 64,000 mph
Mars
• 4th planet
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Diameter: 4,200 miles
Average temperature: -81 degrees F
Distance from the sun: 142 million miles
Length of day: 24.62 hours
Length of year: 687 days (1.88 years)
Natural satellites: 2
Mars continued
• Special characteristics:
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“Red Planet” – red soil contains rust
Dark blue-gray/greenish “seas”
No water on surface, frozen water beneath surface
Thin air, mostly carbon dioxide
1997 – Mars Pathfinder landed on Mars
Present Day: Spirit and Opportunity rovers
It would take 5 minutes to travel to Mars at the speed
of light
– Named for Roman god of war
Mars
North is at the center, south is at both ends
The Outer Planets
Jupiter, Saturn,
Uranus, Neptune
Jupiter
• 5th planet
• Diameter: 88,915 miles
• Average temperature:
-234 degrees F
• Distance from the sun:
484 million miles
• Length of day: 9 hours
• Length of year: 12 years
• Natural satellites: 62
Jupiter continued
• Special characteristics:
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Largest planet
Giant ball of gas
Heavy pressure turns gas into liquid
Giant red spot – giant storm that has lasted hundreds
of years
Stripes and swirls are cloudy, windy clouds of
ammonia and water
Poisonous atmosphere – hydrogen and helium
49 moons, 3 rings (“mini solar system”)
Named for the king of ancient Roman gods
Saturn
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6th planet
Diameter: 75,000 miles
Average temperature: -288 degrees F
Distance from the sun: 886 million miles
Length of day: 11 hours
Length of year: 30 years
Natural satellites: at least 53
Saturn continued
• Special characteristics:
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First viewed through a telescope by Galileo in 1610
Made of hydrogen, helium and methane
No solid surface
Pressure makes gas into liquid
Yellow and white clouds
“Jewel” of our solar system – 6 major rings
Speed of wind at equator: 1,100 mph
Named for the Roman god of agriculture
Uranus
(YOOR un nus)
• 7th planet
• Diameter: 31,760 miles
• Average temperature: -357 degrees F
(core temperature 9,000 degrees F)
• Distance from the sun: 1.7 billion miles
• Length of day: 17 hours
• Length of year: 84 years
• Natural satellites: 27
Uranus continued
• Special characteristics:
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Tilted sideways
11 rings
No solid surface
Blue-green color due to methane gas
Atmosphere: hydrogen, helium, methane, water,
ammonia
– Named for Roman god – father of the Titans
– Tremendous pressure
– Seasons last 20 years
Neptune
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8th planet
Diameter: 30,700 miles
Average temperature: -353 degrees F
Distance from the sun: 2.8 billion miles
Length of day: 16 hours
Length of year: 165 years (2011)
Natural satellites: 13
Neptune continued
• Special characteristics:
– Blue color from methane gas
– Located through math, rather than
observation
– Incredible pressure
– May have a super hot ocean
– Winds: 1,200 mph
– Named for the Roman god of the sea
– Invisible to naked eye
– 6 rings
Dwarf Planet
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Orbits the sun
Has sufficient mass to be nearly round
Is not a satellite
Does not clear the neighborhood around
its orbit
• Could be called “plutoid” if located beyond
Neptune
Dwarf Planets
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Pluto
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Previously known as the ninth planet
Average temperature: -356 degrees F
Distance from the sun: 4.6 billion miles
Length of day: 6.4 Earth days
Length of year: 248 years
Natural satellites: 3
Orbit crosses Neptune’s orbit
UB313 or Eris
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10 billion miles from the sun
Takes twice as long as Pluto to orbit the sun
Dwarf Planets
• Ceres
– Located in the asteroid belt between Mars and Jupiter
• MakeMake (new official name for Dwarf Planet
136472 2005 FY9)
– Located beyond Neptune
• Haumea (new official name for Dwarf Planet
136108 2003 EL61, originally called "Santa.“)
– Located in the Kuiper Belt
Credits
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Scott Foresman Science
www.nasa.gov
Scholastic News
Google Images
Dictionary.com