https://www.khanacademy.org/science/bmc-grade-9-science/x345505a97fc4a662:observing-space-telescopes/x345505a97fc4a662:space-telescope/v/refracting-reflecting-telescopes 2026-02-28T16:20:46.436623441Z Refracting & Reflecting Telescopes What kinds of telescopes help us observe space using visible light? In this video, explore the two main types of visible light telescopes — Refracting and Reflecting. Learn how Newtonian and Cassegrain designs work, and compare the advantages and disadvantages of each. Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Refracting & Reflecting Telescopes What kinds of telescopes help us observe space using visible light? In this video, explore the two main types of visible light telescopes — Refracting and Reflecting. Learn how Newtonian and Cassegrain designs work, and compare the advantages and disadvantages of each. https://cdn.kastatic.org/ka-youtube-converted/ZfbrDtaLzmc.mp4/ZfbrDtaLzmc.mp4 513 Telescopes https://www.khanacademy.org/science/bmc-grade-9-science/x345505a97fc4a662:observing-space-telescopes/x345505a97fc4a662:space-telescope/e/optical-reflecting-telescopes 2025-12-18T18:40:53.641757593Z Optical telescopes This exercise introduces students to optical telescopes, their structure, working principles, and uses. It builds both factual recall and understanding through varied question types, based on the Class 9 subsection on optical telescopes. Yajurva Joshi exercise