ASTR 103 Lecture Notes - Lecture 6: Terrestrial Planet, Meteoroid, Impact Crater

• School: George Mason University
• Department: Astronomy
• Course: ASTR 103
• Professor: Geller

Document Summary

There are two broad categories of planets: earth-like (terrestrial) and jupiter-like (jovian) All of the planets orbit the sun in the same direction and in almost the same plane. Most of the planets have nearly circular orbits. The average density of any substance depends in part on its composition. An sinks in a fluid if its average density is greater than that of the fluid, but it rises if its average density is less than that of the fluid. The terrestrial planets are made of rocky materials and have dense iron cores, which give these planets high average densities. The jovian planets are composed primarily of light elements, such as hydrogen and helium, which gives these planets low average densities. Relatively small (with diameters of 5,000 to 13,000 km) High average densities (4,000 to 55,000 kg/m^3. Jupiter, saturn, uranus and neptune are jovian planets. Pluto (dwarf planet) is not terrestrial or jovian. Smaller than any of the terrestrial planets.