The terrestrial planet cores contain mostly metal because :

The terrestrial planet cores contain mostly metal because
 
  A) the entire planets are made mostly of metal.
  B) metals condensed first in the solar nebula and the rocks then accreted around them.
  C) metals sank to the center during a time when the interiors were molten throughout.
  D) radioactivity created metals in the core from the decay of uranium.
  E) convection carried the metals to the core.

Question 2

What is the source of Jupiter's intense radio waves and magnetism?
 
  A) charged particles trapped in Jupiter's solid iron core similar to Earth
  B) liquid metallic hydrogen swirling in the rapidly spinning mantle
  C) the ionized sulfur ejected into a torus around Jupiter by Io
  D) the auroral displays in the polar regions, just like with the Earth
  E) a liquid iron and nickel outer core, just like the Earth's magnetic field

Question 3

The twinkling of starlight and the focusing of images by lenses are due to ________ of light.
 
  Fill in the blank(s) with correct word

Question 4

Define intelligent civilization according to Drake.
 
  What will be an ideal response?

Question 5

Why have very few planets with low mass (comparable to Mars or Mercury) been found?
 
  A) These small planets are very rare.
  B) Low mass planets do not produce large enough radial velocity changes in their stars.
  C) High mass planets are blocking our views of low mass planets.
  D) Hot Jupiters have ejected most low mass planets from their solar systems.
  E) Low mass planets are too far from their parent stars to receive enough light to make them visible from Earth.

Question 6

Do you think it is possible that a carbon star could harbor an advanced civilization? Explain your reasoning.
 
  What will be an ideal response?

Question 7

The GAIA mission obtains astrometric data of stars with accuracy in some cases better than 10 microarcseconds. In terms of angular width, what is this equal to?
 
  A) A human hair viewed from a distance of 20 miles
  B) A human hair viewed from a distance of 200 miles
  C) A human hair viewed from a distance of 2000 miles
  D) A human hair viewed from a distance of 20000 miles