Stars twinkle because Earth’s atmosphere bends their light. Planets do not twinkle because they are closer and appear larger. Here is why, and how to tell them apart without a telescope.
Most people assume a telescope’s main job is magnification. It is not — it is light collection. That one distinction explains almost everything about how do telescopes work, why big ones cost a fortune, and why the numbers printed on the box are mostly marketing. The Two Jobs Every Telescope Does Your pupil is about … Read more