General orientation to the Solar System II

First let's focus our minds. To what general amatory of planetary body do the following things belong?

The Solar System We begin survey near the Sun.

The Terrestrial Planets I: Mercury


Mercury and the Moon to scale

Mercury

Physical specs:

Orbital specs:


Points of interest:


  • Principles of Stratigraphy: The rules we used above to determine the relative ages of features is fundamental to geology. Without them, we had no means of telling the relative ages of geologic features prior to the development of radiometric dating. For planets where we have no physical specimens, they remain our only iron-clad method. To review, they are: Commit these to memory now, please.

  • Density: The ratio of a substance's mass to its volume is its density. The SI standard units of density are 103kilograms/cubic meter, i.e. 103kg m-3. In practice we often express this as g cm-3. Some common materials and their densities: A planet's density is a function of: As the plot on the right shows, Mercury is much denser than we would expect for a planet its size. It has long been expected that it has a very large metallic core. Recent Messenger data have confirmed and reemphasized this. 85% of Mercury's radius, it seems, is taken up by its core. More than previously thought. (Compare with 45% for Earth.) Why this is so is an open question.

    The Terrestrial Planets II: Venus


    Venus, Earth, and the Moon to scale

    Venus (Right, with Earth and the moon for scale)

    Physical specs:

    Orbital specs:


    Points of interest:



    Key concepts and vocabulary. Understand these or you're toast: