2024年的日行迹
See Explanation. Clicking on the picture will download the highest resolution version available.
请参阅说明。单击图片将下载可用的最高分辨率版本。
2021年的天空
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…
美丽的春分日落
2022年3月20日 A Picturesque Equinox Sunset Image Credit & Copyright: Roland Christen Explanation: What’s that at the end of the road? The Sun. Many towns have roads that run east – west, and on two days each year, the Sun rises and sets right down the middle. Today is one of those days: an equinox. Not only is today a day of equal night (“aequus”-“nox”) and day time, but also a day when the sun rises precisely to the east and sets due west. Featured here is a picturesque road in northwest Illinois, USA that runs approximately east -west. The image was taken during the March Equinox of 2015, and shows the Sun down the road at sunset. In many cultures, this March equinox is taken…
南极的日出
2021年10月5日 Sunrise at the South Pole Image Credit & Copyright: Martin Wolf (U. Wisconsin), IceCube Neutrino Obs., NSF; ht: Alice Allen Explanation: Sunrise at the South Pole is different. Usually a welcome sight, it follows months of darkness — and begins months of sunshine. At Earth’s poles, it can take weeks for the Sun to rise, in contrast with hours at any mid-latitude location. Sunrise at a pole is caused by the tilt of the Earth as it orbits the Sun, not by the rotation of the Earth. Although at a pole, an airless Earth would first see first Sun at an equinox, the lensing effect of the Earth’s atmosphere and the size of the solar disk causes the top of the Sun to appear…
获月的迹线
2021年9月23日 Harvest Moon Trail Image Credit & Copyright: Mike Cohea Explanation: Famed in festival, story, and song the best known full moon is the Harvest Moon. For northern hemisphere dwellers that’s a traditional name of the full moon nearest the September equinox. Seen from Saunderstown, Rhode Island, planet Earth, this Harvest Moon left a broad streak of warm hues as it rose through a twilight sky over the Newport Bridge. On September 20 its trail was captured in a single 22 minute exposure using a dense filter and a digital camera. Only two days later the September equinox marked a change of season and the beginning of autumn in the north. In fact, recognizing a season as the time between solstice and equinox, this Harvest…
春天的满月
2020 April 10 Full Moon of Spring Image Credit & Copyright: Jeff Dai (TWAN) Explanation: From home this Full Moon looked bright. Around our fair planet it rose as the Sun set on April 7/8, the first Full Moon after the vernal equinox and the start of northern hemisphere spring. April’s full lunar phase was also near perigee, the closest point in the Moon’s elliptical orbit. In fact, it was nearer perigee than any other Full Moon of 2020 making it the brightest Full Moon of the year. To create the visual experience a range of exposures were blended to capture the emerging foreground foliage and bright lunar disk. The hopefull image of spring was recorded from a home garden in skies over Chongqing, China….
蒙特利尔清晨天空中的行星和月亮
2020 March 20 Morning, Planets, Moon and Montreal Image Credit & Copyright: Arnaud Mariat Explanation: Dawn’s early light came to Montreal, northern planet Earth, on March 18, the day before the vernal equinox. At the end of that nearly equal night the Moon stands above a dense constellation of urban lights in this serene city and skyscape. Of course the Moon’s waning crescent faces toward the rising Sun. Skygazers could easily spot bright Jupiter just above the Moon, close on the sky to a fainter Mars. Saturn, a telescopic favorite, is just a pinprick of light below and farther left of the closer conjunction of Moon, Jupiter and Mars. Near the ecliptic, even Mercury is rising along a line extended to the horizon from Jupiter…
日行迹
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 River and the capital city of Hungary. Looking south from Budapest’s Margaret Bridge it combines digital frames taken at exactly the same time of day (11:44 CET) on dates between 2018 September 24 and 2019 September 15. That puts the metropolitan Pest on the left, regal Buda on the right, and the positions of the Sun on the solstice dates at the top and bottom of the analemma…
秋分：从冬至到夏至的太阳
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’s southern hemisphere. An equinox occurs midway between the two solstices, when the days and nights are the least equal. The featured picture is a composite of hourly images taken of the Sun above Bursa, Turkey on key days from solstice to equinox to solstice. The bottom Sun band was taken during the north’s winter solstice in 2007 December, when the Sun could not rise…