Slide 1
Prentice Hall EARTH SCIENCE
Tarbuck Lutgens
Slide 2
Chapter 23
Touring Our
Solar System
Slide 3
23.1 The Solar System
The terrestrial planets are planets that are small and rocky—Mercury, Venus, Earth, and Mars.
The Jovian planets are the huge gas giants—Jupiter, Saturn, Uranus, and Neptune.
Pluto does not fit into either the Jovian or the terrestrial category.
Slide 4
Slide 5
23.1 The Solar System
Size is the most obvious difference between the terrestrial and Jovian planets.
Density, chemical makeup, and rate of rotation are other ways in which the two groups of planets differ.
Slide 6
Slide 7
23.1 The Solar System
The Interiors of the Planets
• The substances that make up the planets are divided into three groups: gases, rocks, and ices.
The Atmosphere of the Planets
• The Jovian planets have very thick atmospheres of hydrogen, helium, methane, and ammonia.
• By contrast, the terrestrial planets, including Earth, have meager atmospheres at best.
Slide 8
Slide 9
23.1 The Solar System
Nebular Theory
• A nebula is a cloud of gas and/or dust in space.
• According to the nebular theory, the sun and planets formed from a rotating disk of dust and gases.
Slide 10
23.1 The Solar System
Planetesimals
• Planetesimals are small, irregularly shaped bodies formed by colliding matter.
Slide 11
Slide 12
Planetary Composition, Distance from the Sun, and Melting Point
Slide 13
23.2 The Terrestrial Planets
Mercury is the innermost and second smallest planet; it is hardly larger than Earth’s moon.