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2022年9月18日 Analemma over the Callanish Stones Image Credit & Copyright: Giuseppe Petricca Explanation: If you went outside at the same time every day and took a picture that included the Sun, how would the Sun’s position change? A more visual answer to that question is an analemma, a composite image taken from the same spot at the same time over t...
2022年6月21日 Analemma over Taipei Image Credit & Copyright: Meiying Lee Explanation: Does the Sun return to the same spot on the sky every day? No. A better and more visual answer to that question is an analemma, a composite of images taken at the same time and from the same place over the course of a year. The featured analemma was compiled at 4:30 pm ma...
2022年3月21日 The Sky in 2021 Image Credit & Copyright: Cees Bassa (Netherlands Institute for Radio Astronomy) Explanation: What if you could see the entire sky — all at once — for an entire year? That, very nearly, is what is pictured here. Every 15 minutes during 2021, an all-sky camera took an image of the sky over the Netherlands. Central c...
2021年12月21日 Solstice Sun and Milky Way Composite Image Credit & Copyright: Stefan Seip (TWAN) Explanation: Welcome to December’s solstice, first day of winter in the north and summer for the southern hemisphere. Astronomical markers of the seasons, solstice and equinox dates are based on the Sun’s place in its annual journey along the eclipt...
2021年06月20日 Sunrise Solstice over Stonehenge Image Credit & Copyright: Max Alexander, STFC, SPL Explanation: Today the Sun reaches its northernmost point in planet Earth’s sky. Called a solstice, many cultures mark this date as a change of seasons — from spring to summer in Earth’s Northern Hemisphere and from fall to winter in Earth&#...
2021年06月19日 Northern Summer Twilight Image Credit & Copyright: Justin Anderson Explanation: Nights grow shorter and days grow longer as the summer solstice approaches in the north. Usually seen at high latitudes in summer months, noctilucent or night shining clouds begin to make their appearance. Drifting near the edge of space about 80 kilometers above...
2020年12月21日 Solstice: Sunrises Around the Year Image Credit & Copyright: Zaid M. Al-Abbadi Explanation: Does the Sun always rise in the same direction? No. As the months change, the direction toward the rising Sun changes, too. The featured image shows the direction of sunrise every month during 2019 as seen from near the city of Amman, Jordan. The came...