Have you ever wondered why the sky is blue but space is black? The answer lies in how sunlight interacts with Earth's atmosphere. Sunlight is made of many colors like red, orange, yellow, green, blue, indigo, and violet. Each color has different wave lengths. Blue light waves are short and scatter more easily. When sunlight enters Earth's atmosphere, tiny gas molecules scatter blue light in all directions. This scattered blue light reaches our eyes, making the sky look blue. Colors with longer waves, like red and yellow, mostly travel straight and don't scatter much. Near the horizon, the sky appears lighter or whitish because sunlight passes through more air, causing blue light to scatter multiple times and mix with other colors. Reflections from land and water add to this effect. Sunsets are red or orange because the sun's light travels through a thicker atmosphere, scattering away blue light. We then see mainly red, orange, and yellow colors. Dust and pollution can make sunsets look even more intense. Other planets have different sky colors due to their atmospheres. For example, Mars has a thin carbon dioxide atmosphere with dust, making its sky orange or red during the day. Surprisingly, Mars sunsets appear bluish-grey. Space looks black because it has no atmosphere to scatter sunlight. Without scattered light, the sky is dark, even though the sun shines brightly. In short, the blue sky we enjoy is thanks to Earth's atmosphere scattering sunlight. Without it, the sky would be as dark as space. Next time you watch a sunset or see the blue sky, remember it is sunlight dancing through the air.