Problem Set 3 Solution
27 Sep 2004
11 October 2004
No late homework and homework counts 40% of the total grade.
Each question / problem is of equal weight and equals 5 points.
Review and Discussion – 1, 8, 10, 17, 20
3, 5, 9, 10, 14
REVIEW AND DISCUSSION
1. Name and describe all the different types of objects found in the solar system. Give one distinguishing
characteristic of each. Include a mention of interplanetary space.
In our solar system there are 9 planets, 1 Sun (star), 136 (known) moons, asteroids, meteoroids, comets,
and interplanetary dust. There are at least two basic types of planet, terrestrial and jovian, found in the
inner and outer parts of the solar system. The terrestrial planets are all found close to the Sun, within 1.5
AU. The jovian planets are scattered out at much greater distances, from about 5 to 30 AU. Pluto, which
is neither a jovian or terrestrial planet, is at about 40 AU. The space between these objects is a better
vacuum (space void of matter) than can be produced on Earth, although it contains much more material in
the form of dust and gas than found between the stars.
8. Name three important differences between the terrestrial planets and the jovian planets.
Three differences between jovian and terrestrial planets: (1) location in the solar system, (2) size of the
planets, (3) density. The terrestrial planets are in the inner 1.5 AU of the solar system; the jovian planets
are scattered from 5 to 30 AU. The jovian planets are much larger than the terrestrial planets. Terrestrial
planets have a much higher density than the jovian planets, which indicates a fundamental difference in
composition. Terrestrial planets are rocky, jovian planets are made up of light elements.
10. Why are asteroids and meteoroids important to planetary scientists?
Asteroids and meteoroids are important because they often contain material that has undergone little
change since the solar system was formed. The surface material of the Earth and Moon, for instance, has
changed greatly over time, thus little is known about the original conditions under which they were
What is the key ingredient in the modern condensation theory of the solar system’s origin that was
missing or unknown in the nebular theory?
Interstellar dust within the early solar nebula is the key ingredient for the modem condensation theory for
the formation of the solar system.
20. How did the temperature structure of the solar nebula determine planetary composition?