1. Concepts 2. Solar System Origin 3. Planetary Processes 4. Earth Processes 5. Meteorites
6. Our Moon 7. Remote Sensing 8. Mercury 9. Mars 10. Venus, Our Twin
11. Jupiter & Jovian Moons 12. Saturn, Rings & Moons 13. Uranus 14. Neptune 15. Pluto, Charon & Comets

Planetary Science Concepts

Read Chapters 1 and 2 in, "The New Solar System", 4th edition

Introduction: A Planetary Perspective

Only in the past few decades have humans realized the importance of studying our neighbors within the solar system. Beginning with the first launch of Earth-orbiting satellites in the late 1950's by the former Soviet Union and the United States of America, and continuing with missions to all planets (except Pluto) in the solar system, humans began a serious trek toward understanding other worlds. Currently, Earth's space program represents a relatively unselfish cooperation among numerous countries, mostly in North America, Europe and Asia.

Much of the impetus for planetary probing resulted from global competition to develop new technology and build better systems for communications, resource evaluation and, of course, national defense. Moreover, we are faced with the overwhelming problem of human population on this planet compounded with dwindling resources.


In his 1993 textbook Moons and Planets, Hartmann (see references below) points out that the idea of space colonization is often associated with the concept of utilizing resources obtained on other planetary bodies.


He reminds us that environmental awareness on Earth has taught us three important lessons in planetary science:



People first went to the Moon in 1969 on the Apollo 11 mission and returned safely with precious lunar rocks and soils. We have maintained space stations around Earth and demonstrated the utility of performing experiments and developing technology in near zero-gravity regimes. In the summer of 1997, the entire world witnessed the first Mars Pathfinder mission and saw a small-wheeled robot called Sojourner roll off a ramp and away from its parent capsule to analyze rocks on the martian surface.

There is little wonder in why we intend to explore our solar system, but we have to be efficient in our means of travel and scientific inquiry. A high level of efficiency depends on using what knowledge is gained from previous studies to evaluate the best means of developing and utilizing future studies. All disciplines of science, engineering, humanities, art, law, medicine, and other facets of human society are becoming involved in planetary exploration and development. We need to learn as much as possible about our neighbors in the solar system so that we make wise decisions concerning the fate of natural resources, ecosystems, and humanity itself!

The Solar System -- Overview 

Below are links to excellent sites that you may want to really get to know. Pick a few of your favorites to use during this and the other modules. There are many, many, many !!! more, but if you aren't careful you will get caught up in trying to search too many. That's why pick a few of your favorites to bookmark for future reference.

Welcome to the Planets, Planetary Date System -- http://pds.jpl.nasa.gov/planets/
Solar System Guide -- http://stardate.org/resources/ssguide/
View of the Solar System -- http://www.solarviews.com/eng/homepage.htm
moon Solar System Exploration -NASA-- http://solarsystem.nasa.gov/planets/
USGS Astrogeology Science Center
The Planetary Society -- http://www.planetary.org/

If you know the order of the planets, your life will be easier for the rest of this course. So take some time to learn the order before proceeding.

Use this mnemonic: . . ."My Very Excellent Mother Just Sent Us Nine Pizzas."

The Solar system = one star + nine planets + about 60 moons + thousands of asteroids + billions of meteoroids and comets -- PLUS THOUSANDS OF PIECES OF SPACE JUNK ORBITING THE EARTH!
The Sun makes up about 99.87 percent of the mass of the solar system (Jupiter has most of the rest!)

Assignment # 1 - linked here as a pdf document.

Just for fun let's put the Solar System into perspective

If the Sun were 3 m in diameter (about the height of a basketball hoop) then . . . .

Okay, those weren't all that accurate, but they help. Below are the Actual Solar System Dimensions.

Planetary Body Diameter Relative to Earth Diameter (km) Average Distance from Sun Relative to Earth's Diameter Average Distance from Sun 106 km)
Sun 109.0 1,390,400 --  
Mercury 0.383 4,886 4,540 59.7
Venus 0.948 12,093 8,480 108.2
Earth 1.000 12,756 11,700 149.2
Moon 0.273 3,482 30.2*  
Mars 0.533 6,799 17,900 228.3
Jupiter 11.200 142,867 61,000 778.1
Saturn 9.450 120,544 112,000 1,429
Uranus 4.020 51,279 225,000 2,870
Neptune 3.880 49,493 352,000 4,490
Pluto 0.180 2,296 463,000 5,906
* Average Distance from the Earth    

Study the Planetary Data Table below, for general relations to Earth. Compare to this table.  Draw some conclusions about where each type of planet occurs in the solar system and write down the possible reasons for the size and location of each planet.

Solar System data in terms of Earth:

Planetary Body Orbital Period Volume Mass Surface Gravity Rotational Period
Sun -- 1,300,000 333,000 28.00 24.6*
Mercury 0.241 0.056 0.055 0.37 58.7
Venus 0.615 0.860 0.815 0.91 -243.0+
Earth 1 1 1 1 1
Moon 0.0748 0.020 0.012 0.170 27.3
Mars 1.88 0.150 0.107 0.380 1.03
Jupiter 11.9 1300.0 318.0 2.300 0.411
Saturn 29.5 760.0 95.2 0.880 0.428
Uranus 84.0 50.0 14.5 0.960 -0.720+
Neptune 165.0 45.0 17.1 1.300 0.671
Pluto 248.0 0.0055 0.0023 0.073 6.390
*Rotational period at the equator of the Sun.
+Rotation is retrograde, opposite to rotation of the Earth.

Assignment # 2 and #3 - linked here as a pdf document.
Review the General Properties of all Planets, the Major Moons, Asteroids and Comets in the book.


Vocabulary words to know:     Glossary
Apollo 11
natural resources
Solar System
meteor, meteorite
primitive nebular material
solar nebula

Some other websites that might be helpful:

P.O.E.T.R.Y. K-12 Space Science Site
Students for the Exploration and Development of Space
The Nine Planets - A Multimedia Tour of the Solar System
Lunar and Planetary Institute -- Slide sets that will be used throughout this course.


Greeley R. (1993) Planetary Landscapes. Chapman and Hall, New York. 286 pp.

Hartmann, W.K., 1993, Moons and Planets, 3rd edition. Belmont, CA: Wadsworth Publishing Company.

End Of The Module
On to Module 2