Bodies of the Solar System
There are
two distinct planetary types
within the solar system
What role did gravity play in shaping the planets?
Was there a thermal gradient across the solar system? Did it get cooler further away from the Sun?
Was there a pressure gradient (solar wind) across the solar system? Did it get weaker further away from the Sun?
Was the Sun the only source of heat and light in the solar system?
Terrestrial planets (inner planets)
Mercury, Venus, Earth & Mars
Metallic cores (iron and nickel, surrounded by rock)
High density
Little atmosphere
No rings, few satellites
Jovian planets (outer planets)
Jupiter, Saturn, Neptune, Uranus & Pluto
Metallic cores (iron and nickel, surrounded by liquid helium)
Low density
Lots of atmosphere
Most have rings, and numerous satellites
What about comets (dirty snowballs), meteors (shooting stars), and asteroids (minor planets)?
Where do they fit into our picture?
What are they made of?
Where do their orbits take them?
Are they related to the cratering record of the planets and moons?
Comet Hale-Bopp. [Malcolm Ellis]
Fragment of Asteroid Vesta.
[NASA/HST, R. Kempton]
Image of Asteroid Eros.
[NASA/NEAR]
