The moon appears yellow tonight primarily because it is near the horizon and the light it reflects has to travel through a thicker layer of Earth's atmosphere. This atmosphere scatters shorter blue wavelengths of light and allows longer red and yellow wavelengths to pass through, giving the moon a yellow or orange hue. Additionally, atmospheric conditions such as dust, pollution, or smoke can enhance this yellow coloring by further scattering the shorter wavelengths. Tonight is also special because it is the October 2025 Harvest Moon, which is a supermoon — the moon is closer to Earth in its orbit, making it appear larger and brighter. This combination, along with the atmospheric effects near the horizon, makes the moon stand out with a striking yellow color.
