三条日轨

三条日轨

ByNASA中文

2023年6月21日 Three Sun Paths Image Credit & Copyright: Marcella Giulia Pace & Giuseppe De Donà Explanation: Does the Sun follow the same path every day? No. The Sun’s path changes during the year, tracing a longer route during the summer than the winter. Pictured here, the Sun’s arc was captured from noon to sunset on three days, from highest in the sky to lowest: summer solstice, equinox, and winter solstice. The images were taken near Gatto Corvino Village in Sicily, Italy in 2020 and 2021. The path and time the Sun spends in the sky is more important in determining the season than how close the Earth is to the Sun. In fact, the Earth is closest to the Sun in January, during northern winter….

春分的羽蛇神金字塔

春分的羽蛇神金字塔

ByNASA中文

2023年3月19日 Equinox at the Pyramid of the Feathered Serpent Image Credit & Copyright: Robert Fedez Explanation: To see the feathered serpent descend the Mayan pyramid requires exquisite timing. You must visit El Castillo — in Mexico’s Yucatán Peninsula — near an equinox. Then, during the late afternoon if the sky is clear, the pyramid’s own shadows create triangles that merge into the famous illusion of a slithering viper. Also known as the Temple of Kukulkan, the impressive step-pyramid stands 30 meters tall and 55 meters wide at the base. Built up as a series of square terraces by the pre-Columbian civilization between the 9th and 12th century, the structure can be used as a calendar and is noted for astronomical alignments. The featured composite image…

北纬63度的日晕

北纬63度的日晕

ByNASA中文

2022年12月21日 Sun Halo at Sixty-three Degrees North Image Credit & Copyright: Goran Strand Explanation: Happy Solstice! Today is the December solstice, marking an astronomical beginning of summer in the southern hemisphere and winter in the north. On its yearly trek through planet Earth’s skies, at this solstice the Sun reaches its southern most declination, 23.5 degrees south, at 21:48 UTC. About 4 days ago the Sun was near this seasonal southern limit and so only just above the horizon at local noon over Ostersund in central Sweden. This view looking over the far northern lakeside city finds the midday Sun with a beautiful solar ice halo. Naturally occurring atmospheric ice crystals can produce the tantalizing halo displays, refracting and reflecting the sunlight through their hexagonal…

世界各地的秋分日出

世界各地的秋分日出

ByNASA中文

2022年9月30日 Equinox Sunrise Around the World Collage Image Copyright: Luca Vanzella Explanation: A planet-wide collaboration resulted in this remarkable array of sunrise photographs taken around the September 2022 equinox. The images were contributed by 24 photographers, one in each of 24 nautical time zones around the world. Unlike more complicated civil time zone boundaries, the 24 nautical time zones are simply 15 degree longitude bands corresponding to 1 hour steps that span the globe. Start at the upper right for the first to experience a sunrise in the nautical time zone corresponding to Coordinated Universal Time (UTC) + 12 hours. In that time zone, the photographer was located in Christchurch, New Zealand. Travel to the west by looking down the column and then moving to…

9月日出时分的光和影

9月日出时分的光和影

ByNASA中文

2022年9月24日 September Sunrise Shadows Image Credit & Copyright: Donato Lioce Explanation: The defining astronomical moment for this September’s equinox was on Friday, September 23, 2022 at 01:03 UTC, when the Sun crossed the celestial equator moving south in its yearly journey through planet Earth’s sky. That marked the beginning of fall for our fair planet in the northern hemisphere and spring in the southern hemisphere, when day and night are nearly equal around the globe. Of course, if you celebrate the astronomical change of seasons by watching a sunrise you can also look for crepuscular rays. The shadows cast by clouds can have a dramatic appearance in the twilight sky during any sunrise or sunset. Due to perspective, the parallel shadows will seem to point…

秋分: 卡拉尼什巨石阵上空的日行迹

秋分: 卡拉尼什巨石阵上空的日行迹

ByNASA中文

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 the course of a year. The featured analemma was composed from images taken every few days at noon near the village of Callanish in the Outer Hebrides in Scotland, UK. In the foreground are the Callanish Stones, a stone circle built around 2700 BC during humanity’s Bronze Age. It is not known if the placement of the Callanish Stones has or had astronomical significance. The…

西西里上空的获月

西西里上空的获月

ByNASA中文

2022年9月15日 Harvest Moon over Sicily Image Credit & Copyright: Dario Giannobile Explanation: For northern hemisphere dwellers, September’s Full Moon was the Harvest Moon. Reflecting warm hues at sunset it rises over the historic town of Castiglione di Sicilia in this telephoto view from September 9. Famed in festival, story, and song Harvest Moon is just the traditional name of the full moon nearest the autumnal equinox. According to lore the name is a fitting one. Despite the diminishing daylight hours as the growing season drew to a close, farmers could harvest crops by the light of a full moon shining on from dusk to dawn. Harvest Full Moon 2022: Notable Submissions to APOD Tomorrow’s picture: pixels in space 西西里上空的获月 影像提供与版权: Dario Giannobile 说明: 对于北半球的住民来说，9月的满月是丰收的获月。在这幅摄于9月9日的长焦镜头里像里，它在日落时，带着温暖的色调从历史悠久的西西里堡小镇后方升起。以节日、故事和歌曲而著称的获月，是最接近秋分的满月之传统名称，而它显然是这轮满月很贴切的称号。因为随着生长季节接近尾端，白昼渐短，但农民仍然可以在黄昏到黎明彻夜普照的月光下收割庄稼。 2022年获月:…

台北上空的日行迹

台北上空的日行迹

ByNASA中文

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 many afternoons from Taiwan during 2021, with the city skyline of Taipei in the foreground, including tall Taipei 101. The Sun’s location in December — at the December solstice — is shown on the far left, while its location at the June solstice is captured on the far right. Also shown are the positions of the Sun throughout the rest…

2021年的天空

2021年的天空

ByNASA中文

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 columns from these images were then aligned and combined to create the featured keogram, with January at the top, December at the bottom, and the middle of the night running vertically just left of center. What do we see? Most obviously, the daytime sky is mostly blue, while the nighttime sky is mostly black. The twelve light bands crossing the night sky are caused by…