1
The Earth is in constant motion. Each day the earth makes one complete rotation. Each year, the earth makes one orbit of the sun. The first motion is obvious. The second one, however, is muh harder to notice except over a much longer period and can be made visible only by some time and some...
Grade Level   3 4 5 6 7 8 9 10 11 12
Classroom Activities Curricula and Instruction
Save to List
2
In ancient times, sailors found their way by observing stars and other celestial bodies — when they were visible through the clouds, that is. Thus, one of the most important improvements to ocean navigation was the invention of the compass. There is some disagreement about who should get...
Grade Level   6 7 8
Classroom Activities Curricula and Instruction
Save to List