A secondary mirror is a crucial component in many optical systems, particularly in telescopes like the Hubble Space Telescope. It is typically smaller than the primary mirror and is positioned at an angle to reflect light gathered by the primary mirror toward the eyepiece or camera. This design helps to focus the light and improve the overall image quality. In reflecting telescopes, the secondary mirror enhances the telescope's ability to capture and magnify distant celestial objects. By redirecting light, it allows for a more compact design, making telescopes easier to handle and transport while still providing clear and detailed views of the universe.