Planets

Key Concepts

• The Sun is at the center of our solar system. Its strong gravitational pull holds eight major planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune) and other celestial objects in orbit around it.

• The inner planets Mercury, Venus, Earth, and Mars are smaller and mostly solid with minerals similar to those on Earth.

• The outer planets Jupiter, Saturn, Uranus, and Neptune are much larger gaseous masses with rocky cores.

• Models of our solar system have a limited ability to show the actual size, distance, and composition of the objects in our solar system.

• Models of our solar system usually show the order and appearance of the objects within the solar system accurately.

Fundamental Questions

• What are the eight planets of our solar system? What is their position in relation to the Sun?

• How can we remember the order of the planets from the Sun?

• Which planets are smaller? Which planets are bigger?

• What limitations are found when making a model of the solar system?

• How does size affect a model of the solar system? Order? Appearance? Composition?

• What strengths can be found in models of our solar system?

Compare the physical characteristics of stars and planets.

• • Their are 8 planets in our Solar System.

  • The first 4 inner planets (Mercury, Venus, Earth, Mars) are all terrestrial or rocky planets with fewer moons than that outer planets.

  • The last 4 outer planets (Jupiter, Saturn, Uranus, Neptune) are gaseous planets with many moons and farther from the sun.