Solar system review sheet
1. How many planets travel around the sun? List them in order from closest to
furthest from the sun.
● Eight planets travel around the sun
● Order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune
2. What is the geocentric model? What type of orbit do the planets travel on?
● All the objects in the sky moved in circular paths around Earth. Earth was the
center of the solar system.
3. What is the heliocentric model? What type of orbit do the planets travel on?
●
The sun at the center and the addition of more objects. More elongated orbits
aka elliptical orbit.
4. Where is the majority of the solar system's mass located? What percentage of
the solar system's mass is located there?
● More than 99.8% of the mass of the solar system, or about 1.99 × 1030 kg, is
found in the sun.
5. Which apparent motion can be explained by a geocentric model?
The rotation of the earth leading to day and night.
6. What is revolution?
Revolution is the movement of the Earth around the Sun.
7. What is rotation?
The earth does a complete spin on its axis every twenty-four hours, which causes day
and night.
8. What planets are terrestrial? What are they composed of?
● Mars, Earth, Venus and Mercury
● All have roughly the same structure: a central metallic core, mostly iron, with a
surrounding silicate mantle.
9. What planets are Jovian? What are they composed of?
● Neptune, Uranus, Saturn and Jupiter
● Made up of mainly hydrogen and helium
10. What are dwarf planets? Name the dwarf planets in our solar system.
● A celestial body that orbits the sun, has enough mass to assume a nearly round
shape, but are too tiny to be classified as planets.
● In order of distance from the Sun they are: Ceres, Pluto, Haumea, Makemake,
and Eris.
11. What is a nebula?
● a cloud of dust, ice, and gas
12. How did the solar system begin? And when?
● As the nebula collapsed and became smaller, its density and temperature
increased (Material began to coalesce and accumulate in the center)
● As more and more material accumulated, the gravitational pull toward the center
increased.
● Formed roughly 4.6 billion years ago.
13. Why is gravitational pull important in the solar system?
● The gravitational attraction between the sun and each planet keeps the planets in
their orbits.
14. What is the correlation between density and mass in the planets of our solar
system?
In terms of the planets in our solar system, if a planet is more dense, it has less mass
If a planet has more mass, it’s less dense
15. What shape does our solar system resemble?
●
The shape of the solar system resembles a disk.