Every term when I teach astronomy, I give an assignment of an "AstroJournal" which requires, among other things, students to make observations of the moon and read news articles on astronomy and space science. There is a rubric that all the students get so that they will know how they will be graded. In the rubric is a category called "Other" which gives students a chance to put anything in their journal that is related to astronomy or space that does not otherwise fit into a category we've defined for their journal.
It is also, the only place in ANY of my classes where I give something that even resembles "extra credit". Students can get a small amount of bonus points on the AstroJournal by including items in the "Other" category.
One student last semester was really worried that she was going to fail the class (she was by no means in danger of failing at any time, but that's a whole different discussion), so for her "Other" category she made a video that she uploaded to youtube and sent to me.
On the last day of class, student were to turn in their journal. This is when she told me about the video. She explained that she called the video "pale blue dot". I was really surprised, because that was going to be our class discussion of the day. On the last day of class, I have two images that we spend the entire time talking about. One is the Hubble Deep Field and the other is the "Pale Blue Dot" image from the Voyager spacecraft. But this student had taken the initiative to learn about Sagan's "Pale Blue Dot" speech, and put the words with video.
These are the moments that you dream of as a teacher. Enjoy.