Why is this the answer?

The answer is wind because this super clever riddle is playing a wonderful trick on your mind using the idea of a shadow. When you first hear the riddle, you might picture an airplane, a big bird, or maybe a cloud passing over the sun. All of those things make a shadow on the ground when they block the sun's bright light. But let's look at the first clue again: "I pass before the sun." Wind is all around our planet, and it is the reason that clouds, which are made of tiny drops of water, move across the sky. When the wind pushes a big cloud right between you and the sun, that cloud passes "before the sun" and makes things dark for a moment. The cloud is a part of the wind's journey across the sky. Now for the secret clue: "but make no shadow." This is the part that proves the answer is wind. A shadow is a dark shape that is made when a solid object blocks the light. For example, if you stand outside on a sunny day, your body blocks the sunlight, and your dark shape is your shadow. Wind is made of air moving very fast. Air is something we can feel, like when it blows our hair or flies a kite, but it is invisible. Since air is invisible, it is not a solid object that can block the sun's light. It lets the sunlight pass right through it, even when it is moving very quickly. Because the wind itself is just moving air and cannot block the sun, it can never create a shadow on the ground, which makes it the perfect answer to this fun puzzle.