Teach differently. Engage your students.

Galileo saw this.

http://galileo.rice.edu/sci/observations/jupiter_satellites.html

And deduced this in 1610

http://www.is.wayne.edu/mnissani/a&s/light.htm

And I could have lectured about it.  I didn't. Students read, analyzed text.  Discussed the social science implications of a 'mini solar system'.

Then, the students used this applet to collect data

To generate this model for analysis and discussion.

2013.  Make a year of student-centered learning.