The planets in our universe are wondrous to behold. As you study them in your homeschool, this free, printable Planet Facts and Coloring Page Pack will be a useful resource for your elementary-aged student.
In fact, if you have an older child that is bored with astronomy, this might be an activity you want to whip out. (I may or may not have fallen asleep in a planetarium on a field trip once with my children. Awful, I know; but I can relate.) Anyway, you could let the older child color on the front and journal on the back of the pages.
These are a helpful resource for all ages!