... Transfusing sunlight through a a still dark sky, this exceptional display of noctilucent clouds was captured earlier this month above the island of Gotland, Sweden. ... M31: The Andromeda Galaxy . ... Andromeda is the nearest major galaxy to our own Milky Way Galaxy. ... The diffuse light from Andromeda is caused by the hundreds of billions of stars that compose it. ... One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. ...