保护地球, 探索宇宙, 发现文明
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...
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...
Credit: NASA/JPL-Caltech 十二月的天空会发生什么？一场流星雨，一场木星和土星之间的罕见的近距离接触，还有冬至。 Credit: NASA/JPL-Caltech 12月带来了每年最可靠的流星雨之一，也是2020年最好的流星雨之一——双子座流星雨。这场流星雨从12月4日到17日非常活跃，因为地球在小行星法厄同3200轨道上留下的尘埃碎片的痕迹中穿行。这可能是一颗被烧毁的彗星。 双子座流星雨大多数年份都能产生大量的流星，但今年的流星雨更甚。因为流星雨的高峰期正好赶上新月的到来，因此天空变得更暗，没有月光来干扰较暗的流星，双子座流星雨在12月13日夜间至14日早晨达到高峰，前后几天都能看到一些流星活动。北半球整夜都可以观看，当地时间凌晨2点左右最活跃，而对于南半球的观众来说则是在午夜之后观看。...
2019 December 22 Solstice Illuminated: A Year of Sky Video Credit & Copyright: Ken Murphy (MurphLab); Music: Ariel (Moby) Explanation: Can you find which day is the winter solstice? Each panel shows one day. With 360 movie panels, the sky over (almost) an entire year is shown in time lapse format as recorded by a video camera on the roof of the Explorato...
2019 December 21 Solstice to Solstice Solargraph Timelapse Image Credit & Copyright: Sam Cornwell Explanation: The 2019 December Solstice, on the first day of winter in planet Earth’s northern hemisphere and summer in the south, is at 4:19 Universal Time December 22. That’s December 21 for North America, though. Celebrate with a timelapse ani...
2019 September 28 An Analemma of the Sun Image Credit & Copyright: Gyorgy Soponyai Explanation: This week the equinox found the Sun near the middle, but not at the crossing point, of an analemma in its annual trek through planet Earth’s skies. In this scenic view, that graceful, figure-8-shaped curve was intentionally posed above the iconic Danube...
2019 September 23 Equinox: The Sun from Solstice to Solstice Image Credit & Copyright: Tunç Tezel (TWAN) Explanation: Today is an equinox, a date when day and night are equal. Tomorrow, and every day until the next equinox, the night will be longer than the day in Earth’s northern hemisphere, and the day will be longer than the night in Earth’...
2019 June 27 时长越来越长的白昼 影像来源及版权: Gianluca Belgrado 说明：这幅持续拍摄六个月的长曝光影像将从冬至到夏至（2018年12月21日至2019年6月16日）的时间压缩成一个单一的视角。这幅不寻常的影像被称为日轨图，它是由一台高大的管状针孔相机、通过使用一张照相纸拍摄而成。这台简易的相机被固定在意大利.卡萨拉诺的一个单一地点上，并连续不断地记录太阳的日常路径，就像一道炽热的轨迹在感光纸上燃烧一样。这些轨迹上的中断和缺口是由云层造成的。在曝光结束时，我们对纸张进行扫描从而构建出这幅数字影像。当然，从12月开始，太阳轨迹会在临近北半球冬至时落在天空中的较低处。随着白昼时长的增加和6月21日夏至的来临，太阳轨迹会越升越高。 The Longer Days Image Credi...