Live from Mars  Star Census...
This activity is about students making data observations, analyzing the data locally and then sharing their results with one another.
OBJECTIVE
To encourage students to observe the quality of the night sky and to determine the number of stars that can be seen from their local area.
ENGAGE YOUR STUDENTS
Ask students how many stars there are outside at night. Accept all estimates and record them on the chalkboard. Ask how they could go beyond guesses and estimates. Tell students that they are going to devise a way to count the stars in the sky. If you have access, tell them their data will become part of a national, online collaboration.
EXPLORE / EXPLAIN
Ask students to explain the phrase "Twinkle, Twinkle, Little Star". Ask them what "twinkling" means. Explain to students that only stars twinklethe moon and planets do not. As a group, make the predictions as suggested on the activity sheet at this science fair project on stars. Pick a time for students to make nighttime observations of stars.
MATERIALS
 http://quest.arc.nasa.gov/lfm/events/actE.html : measuring activity sheet
 scissors
 ruler
 a protractor
 a compass (to determine North, South, East & West.)
 empty toilet paper tube or paper towel(must be 3 times longer than the distance across the opening!)
EXPAND YOUR PROJECT
Plan a time for students to take a "Star Census". Review with students how to do the counting. If possible, it would be interesting to have students make these observations in different locations (near a city or out in the country) and at different times (when there's a bright moon and when there's no moon). For younger students, you can use fewer observations. Just remember that each observation represents 1/144th of the sky. If students make only 6 observations, they would multiply the total number of stars observed by 24 (which is 144 divided by 6).
