Site MapHelpFeedbackOverview of the Solar System
Overview of the Solar System

<a onClick="'/olcweb/cgi/pluginpop.cgi?it=jpg::::/sites/dl/free/0073512184/506860/chapter07.jpg','popWin', 'width=335,height=430,resizable,scrollbars');" href="#"><img valign="absmiddle" height="16" width="16" border="0" src="/olcweb/styles/shared/linkicons/image.gif"> (17.0K)</a>

Twilight comes and all of the
Visible planets come out.
Venus first, and then Jupiter,
Mars and Saturn and finally
Mercury once more.
Seals bark
On the rocks. I tell Mary
How Kepler never saw Mercury,
How as he lay dying it shone
In his window, too late for him
To see.

Kenneth Rexroth
Protoplasm of Light

Questions to Explore:
  • Why do some planets have atmospheres while others do not?
  • Why does the pressure in the atmosphere of a planet or satellite fall with increasing height?
  • What makes the surfaces of some planets hotter than others?
  • Why are the interiors of planets hot?

AstronomyOnline Learning Center

Home > Chapter 7