Astronomy, Grades 6 - 12: Our Solar System and Beyond (Expanding Science Skills)

Mark Twain Astronomy Book, Middle and High School Earth and Space Science Workbook Covering Our Solar System and Beyond, Classroom or Homeschool Curriculum (Expanding Science Skills Series)

Mark Twain - Meteorology, Grades 6 - 12 (Expanding Science Skills Series)

Mark Twain Earth & Space Science Interactive Books, Grades 5-8, Geology, Oceanography, Meteorology, and Astronomy Books, 5th Grade Workbooks and Up, ... Homeschool Curriculum (Interactive Notebook)