Gemini North and the Big Dipper

From the photographer: “The Gemini Northern 8-meter Telescope seen in moonlight. The telescope is located at Mauna Kea Observatory on the island of Hawaii. The constellation of Ursa Major (Big Bear) is seen on the right. The asterism called “The Big Dipper” is part of the Ursa Major constellation, and is commonly used in the northern hemisphere to locate Polaris (which in this photo is hidden behind the telescope dome).

When the moon is up at night the sky is blue colored, just like it is in the daytime. Our eyes are not sensitive enough to see the color but it is easily recorded in photographs. Moonlight is reflected sunlight, and has a similar color to sunlight (the moon is somewhat brown in color). The daylight sky is blue in color because of scattering of sunlight by air molecules – this scattering is much more efficient for bluer colored light. The same scattering process causes the moonlight and twilight skies to be blue colored. ” – Richard Wainscoat