There is more about the Milky Way that scientists don't know than what they do know—that leaves a lot to discover! A thorough lesson presentation explores the components of the Milky Way Galaxy and their behaviors. 

In 150 BC, Seleucus of Seleucia theorized that the moon causes the tides. Scholars learn about what causes tides by studying the interactions of gravity between the sun, moon, and Earth. They use technology to formalize otherwise...