MES2648049: Great Temple, Yeha, Tigray Region, Ethiopia, Africa (photo) / Bridgeman Images

MES2648052: Great Temple, Yeha, Tigray Region, Ethiopia, Africa (photo) / Bridgeman Images

MES2648055: Great Temple, Yeha, Tigray Region, Ethiopia, Africa (photo) / Bridgeman Images

MES2648056: Great Temple, Yeha, Tigray Region, Ethiopia, Africa (photo) / Bridgeman Images

MES2648060: Yeha Museum, Yeha, Tigray Region, Ethiopia, Africa (photo) / Bridgeman Images

MES2648061: Yeha Museum, Yeha, Tigray Region, Ethiopia, Africa (photo) / Bridgeman Images

MES2648063: Yeha Museum, Yeha, Tigray Region, Ethiopia, Africa (photo) / Bridgeman Images

MES2648071: New Church of Our Lady Mary of Zion, Aksum, Ethiopia, Africa (photo) / Bridgeman Images

MES2648072: New Church of Our Lady Mary of Zion, Aksum, Ethiopia, Africa (photo) / Bridgeman Images

MES2648079: Old Church of Our Lady Mary of Zion, Aksum, Ethiopia, Africa (photo) / Bridgeman Images

MES2648080: Old Church of Our Lady Mary of Zion, Aksum, Ethiopia, Africa (photo) / Bridgeman Images

MES2648084: Ruins of Queen of Sheba's Palace, Dungur, Aksum, Ethiopia, Africa (photo) / Bridgeman Images

MES2648086: Tombs of Kings Kaleb and Gebre Meska, Aksum, Ethiopia, Africa (photo) / Bridgeman Images

MES2648092: Narga Selassie Christian Church, Island of Dek, Lake Tana, Gondar Region, Ethiopia, Africa (photo) / Bridgeman Images

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UTD2881332: Cappella Raggio, Saglieno cemetery, Genova province, Italy 1930s (b/w photo) / Bridgeman Images

UTD2881333: Cappella Raggio, Saglieno cemetery, Genova province, Italy 1930s (b/w photo) / Bridgeman Images

UTD2881337: Pantheon, Saglieno cemetery, Genova province, Italy 1930s (b/w photo) / Bridgeman Images

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MES2913954: Mental Hospital, constriction museum, Reggio Emilia, Emilia Romagna, Italy (b/w photo) / Bridgeman Images

MES2914107: Italia, Abruzzo, Teramo, chiesa S. Maria di Rojo / Bridgeman Images

UTD2891653: A rotary printing presses in the plants of the mechanical engineering company MAN (Maschinenfabrik Augsburg-Nürnberg), Germany 1930s (b/w photo) / Bridgeman Images

MRZ3496958: Portinari Chapel, Apse and bell tower, Basilica of Sant'Eustorgio, Milan, Lombardy, Italy (photo) / Bridgeman Images

PIX4623194: Planetary nebula NGC 6369 in Ophiuchus/HST - NGC 6369 is known to amateur astronomers as the “” Little Ghost Nebula,”” because it appears as a small, ghostly cloud surrounding the faint, dying central star. NGC 6369 lies in the direction of the constellation Ophiuchus, at a distance estimated to be between about 2,000 and 5,000 light - years from Earth. When a star with a mass similar to that of our own Sun nears the end of its lifetime, it expands in size to become a red giant. The red - giant stage ends when the star expels its outer layers into space, producing a faintly glowing nebula. Astronomers call such an object a planetary nebula, because its round shape resembles that of a planet when viewed with a small telescope. The Hubble photograph of NGC 6369, captured with the Wide Field Planetary Camera 2 (WFPC2) in February 2002, reveals remarkable details of the ejection process that are not visible from ground - based telescopes because of the blurring produced by the Earth's atmosphere. The remnant stellar core in the center is now sending out a flood of ultraviolet (UV) light into the surrounding gas. The prominent blue - green ring, nearly a light - year in diameter, marks the location where the energetic UV light has stripped electrons off of atoms in the gas. This process is called ionization. In the redder gas at larger distances from the star, where the UV light is less intense, the ionization process is less advanced. Even farther outside the main body of the nebula, one can see fainter wisps of gas that were lost from the star at the beginning of the ejection process. The color image has been produced by combining WFPC2 pictures taken through filters that isolate light emitted by three different chemical elements with different degrees of ionization. The doughnut - shaped blue - green ring represents light from ionized oxygen atoms that have lost two electrons (blue) and from hydrogen atoms that have lost their single electrons (green). Red marks / Bridgeman Images

PIX5894618: Nochten Coal Mine - Germany / Bridgeman Images