Condensation and the Solar Nebula
Close to the forming Sun the solar nebula was hot (hundreds, even thousands of degrees).
- Far away, temperatures were much lower --,
dropping to nearly absolute zero at the outer edges.
- The local temperature determined what sorts
of materials existed as solids.
- Since the process of accretion builds planets from the solid
particles, the temperature in the solar nebula determines the typical
composition of the planets and satellites.
- Close to the Sun objects are made of metal and rock
- Far from the Sun objects are mostly made of ice (with some
rock and metal)
- How do the outer ``Gas Giant" planets fit into the picture.
- They began like the other planets from the accumulation
of solid planetesimals.
- Since they grew in a region where ice was abundantly available...
- Their cores grew quickly and became sufficiently massive to attract and retain gas directly from the nebula.
- The Jovian planets have slushy cores left over from this
Revised March 28, 2001