This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on the Hubble Space Telescope (HST) and how far away it can detect light. Students look at this telescope and its images and then debate in teams over whether or not large amounts of money should be spent using the HST to search for other planets that may have life on them. It includes objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, an audio-enhanced vocabulary list, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.