SAMPLE EARTH AND SPACE SCIENCE STORIES AND ASSOCIATED COMPREHENSION TESTS
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LEVEL 03 STORY 01:
   
   Matter is anything that takes up space. Most matter exists in one of 
   three phases. They are a solid, a liquid, or a gas. A solid has a 
   definite shape. A liquid takes on the shape of the container it's in. 
   A gas has no shape or specific volume. It fills the space available to 
   it. Energy is the ability to change matter from one phase to another.


LEVEL 03 STORY 01 TEST QUESTIONS:

   1. Matter is anything that
      A. fills a volume
     *B. takes up space
      C. uses energy
   2. A solid
     *A. has a definite shape
      B. takes on the shape of the container it's in
      C. fills the space available to it
   3. A gas
      A. has a definite shape
      B. takes on the shape of the container it's in
     *C. fills the space available to it
   4. Energy is the ability
      A. to use matter
     *B. to change matter
      C. to fill a space


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LEVEL 13 STORY 01:

   What are comets, and where do they come from? In 1950 the Dutch 
   astronomer Jan Oort inferred the existence of what is now called the 
   Oort cloud from the physical evidence of long-period comets entering 
   the solar system. He interpreted the evidence of the comet's orbital 
   distribution with only 19 well-measured orbits; later studies 
   confirmed his findings.

   The Oort cloud is an immense spherical cloud that surrounds our solar 
   system and extends approximately 3 light years, or about 30 trillion 
   kilometers, from the Sun. This region is considered to be the edge of 
   the Sun's sphere of both physical and gravitational influence.

   Within the cloud, comets are typically located tens of millions of 
   kilometers apart. Since they are weakly bound to the sun, passing stars 
   and other forces, such as the Jovian planets, can readily change their 
   orbits, sending them into the inner solar system or out into interstellar 
   space. One sixth of an estimated six trillion icy objects or comets lie 
   in the outermost regions of the cloud, with the remainder found in the 
   relatively dense core.

   The total mass of comets in the Oort cloud is estimated to be about 40 
   times that of Earth. These bodies are believed to have originated at 
   different distances and therefore different temperatures, from the sun, 
   which explains the great diversity of their compositions. Typical 
   noontime temperatures in this region are frigid -- approximately four 
   degrees Celsius above absolute zero.


LEVEL 13 STORY 01 TEST QUESTIONS:

   1. When did Jan Oort infer the existence of the Oort cloud?
      A. 1930
     *B. 1950
      C. 1970
   2. Approximately how far does the Oort cloud extend from the sun?
      A. 3 trillion kilometers
      B. 30 million miles
     *C. 3 light years
   3. Approximately how many comets are found in the Oort cloud?
      A. One million
     *B. Six trillion
      C. Twelve billion
   4. What is the typical temperature in this region?
      A. Four degrees Celsius
      B. Forty degrees Kelvin
     *C. Four degrees above absolute zero