Our Solar System
A Journey to Our Planetary Neighbors
1. Ideas about the night sky have changed over time…
_____________________________-centered model – early Greeks thought planets, Sun, Moon and
stars rotated around the Earth
Modern view –
The sun is the ________________________ of our solar system
All other objects in the solar system _________________________ around the sun in elliptical orbits at
different speeds.
2. How did our solar system form?
A ____________________________ of gas, ice, and dust slowly formed in space, and rotated in space.
The cloud began to ______________________________ and the matter was squeezed into less space.
The cloud became dense, heated up and triggered a nuclear ________________________ reaction that
created the sun.
3. What happened next?
All leftover _____________________________ became the planets and asteroids
The four inner planets – (Mercury, Venus, Earth, and Mars) are small and rocky with iron cores
The four outer planets – (Jupiter, Saturn, Uranus, and Neptune) are large, lightweight, and composed of
gases.
4. Inner Planets
______________________________ - closest to the Sun, smallest planet
Many craters and high cliffs
No true __________________________________ so temperatures can range from -292 to 806° F.
It orbits the sun once every 88 days and is an average of 36 million miles from the sun.
5. Inner Planets
________________________________ – second from the sun and similar to the Earth in size and mass
Mostly smooth volcanic plains
Extremely dense atmosphere of clouds
Carbon dioxide gas traps solar energy resulting in temperatures between 842 to 887° F.
It is an average distance of 67 million miles from the sun and orbits every 225 days
6. Inner Planets
_______________________________ – third planet from the Sun
More than 70 percent of surface is covered with water
Atmosphere consists of several layers, is mostly composed of nitrogen and oxygen, and protects the
surface from meteors and Sun’s radiation
It is an average of 93 million miles away from the sun, and completes its orbit in 365.5 days
7. Inner Planets
_______________________________ – fourth planet from the Sun
Called red planet because of iron oxide in rocks
Polar ice caps made of frozen carbon dioxide and water
Surface contains gullies, mountains and canyons, plains and the largest volcano in the solar system
The thin atmosphere mostly contains carbon dioxide
It is an average of 141 million miles from the Sun, and completes its orbit in 1.9 years
8. Asteroids and Other Objects in Our Solar System
Asteroids – rocks similar to that which formed the planets
Asteroid Belt – group of asteroids that orbit the Sun between the planets Mars and Jupiter
9. Comets
__________________________ - dust and rock particles combined with frozen water, methane, and
ammonia
Halley’s comet (occurs every 76 years), Hale-Bopp (1995)
Look similar to a dirty snowball
The ice and dust vaporize as it approaches the sun
This forms a comets tail
10. Meteoroid, Meteor, and Meteorite
__________________________________ – small pieces of debris in space
__________________________________ – small meteoroid that burns up in Earth’s atmosphere
(falling or shooting star)
__________________________________ – meteoroid that strikes Earth
11. Outer Planets
_________________________________ – Fifth planet from the sun and the largest in our solar system
Atmosphere mainly consists of hydrogen and helium
Surface is suspected to be composed of liquid hydrogen and helium, and may have solid core at the
center
It is an average of 484 million miles from the sun and 11.8 years to complete one orbit
Has 16 moons
12. Outer Planets
_________________________________ – sixth planet from the Sun
Thick outer atmosphere of hydrogen, helium, ammonia, methane, and water vapor
Might have rocky core
Rings that circle around planet are composed of ice and rock particles
It is an average of 887 million miles from the Sun, and completes one orbit in 29.5 years
13. Outer Planets
________________________________ – seventh planet from the sun
Atmosphere of hydrogen, helium, and methane
Rotates on its side
Contains thin, dark rings
It is an average of 1.8 billion miles from the sun, and completes one orbit in 84 years
14. Outer Planets
________________________________ – eighth planet from the Sun
Atmosphere is similar to that of Uranus
Storms on Neptune reveal an active and rapidly changing atmosphere
It is an average of 2.8 billion miles from the sun, and completes its orbit every 165 years