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Sciences and Exploration Directorate

The Edge of Two Worlds

Our planet draws closer to passing behind the Moon in this image captured by the Artemis II crew during their lunar flyby, about six minutes before Earthset. 

ASTRONOMY PICTURE OF THE DAY

The Persistence of Sunlight

This seaside sunset offered a surreal experience, captured in a sea and skyscape from the west coast of Sardinia, Italy, planet Earth. The Daliesque scene is a composition of sequential exposures made with a camera and long telephoto lens. The Sun is not melting, though. Its shifting and fluid appearance as it nears the horizon is caused as refraction along the line of sight changes and creates distorted images or mirages of the reddened solar disk. The changes in atmospheric refraction correspond to atmospheric layers with sharply different temperatures and densities. Another famous but fleeting effect of atmospheric refraction produced by a long sight-line to the setting (or rising) Sun is often called the green flash.