Themes: Comets, Space, Science, Technology, Nonfiction, Tween. Scientists want to know more about comets. They decide to catch one. A spacecraft travels for ten years to reach the comet. What will scientists learn from the mission? Red Rhino Books Nonfiction is the first Hi-Lo children's nonfiction series at a first-grade reading level for students in grades 4–7. Visually appealing fullcolor photographs and illustrations—along with fun fact boxes—keep these books flowing. Also includes prereading comprehension questions along with a 20-word glossary for further reading support.