The moon looks orange tonight primarily because it is close to the horizon, causing its light to pass through a thicker layer of Earth's atmosphere. This extra atmosphere scatters shorter wavelengths of light (blue and violet) more than longer wavelengths (red, orange), so the moon appears orange or red to observers. This effect is similar to why sunsets and sunrises often look orange or red. Additionally, atmospheric particles like dust, pollution, or smoke can enhance this orange hue. The moon may also appear larger near the horizon due to an optical illusion known as the Moon illusion, but the orange color is due to atmospheric light scattering and particles.