金字塔山上空的北斗七星

金字塔山上空的北斗七星

ByNASA中文

2023年12月10日 Big Dipper over Pyramid Mountain Image Credit & Copyright: Steve Cullen Explanation: When did you first learn to identify this group of stars? Although they are familiar to many people around the world, different cultures have associated this asterism with different icons and folklore. Known in the USA as the Big Dipper, the stars are part of a constellation designated by the International Astronomical Union in 1922 as the Great Bear (Ursa Major). The recognized star names of these stars are (left to right) Alkaid, Mizar/Alcor, Alioth, Megrez, Phecda, Merak, and Dubhe. Of course, stars in any given constellation are unlikely to be physically related. But surprisingly, most of the Big Dipper stars do seem to be headed in the same direction as they…

低地球轨道上的空间站

低地球轨道上的空间站

ByNASA中文

2023年1月7日 Space Stations in Low Earth Orbit Image Credit & Copyright: Zarcos Palma Explanation: On January 3, two space stations already illuminated by sunlight in low Earth orbit crossed this dark predawn sky. Moving west to east (left to right) across the composited timelapse image China’s Tiangong Space Station traced the upper trail captured more than an hour before the local sunrise. Seen against a starry background Tiangong passes just below the inverted Big Dipper asterism of Ursa Major near the peak of its bright arc, and above north pole star Polaris. But less than five minutes before, the International Space Station had traced its own sunlit streak across the dark sky. Its trail begins just above the W-shape outlined by the bright stars of…

回顾新智彗星

回顾新智彗星

ByNASA中文

2021年7月31日 Remembering NEOWISE Image Credit & Copyright: Petr Horalek / Institute of Physics in Opava Explanation: It was just last July. If you could see the stars of the Big Dipper, you could find Comet NEOWISE in your evening sky. After sunset denizens of the north could look for the naked-eye comet below the bowl of that famous celestial kitchen utensil and above the northwestern horizon. The comet looked like a fuzzy ‘star’ with a tail, though probably not so long a tail as in this memorable skyview recorded from the Czech Republic on July 23th, 2020, near the comet’s closest approach to planet Earth. Photographs of C/2020 F3 (NEOWISE) often did show the comet’s broad dust tail and fainter but separate bluish ion tail…

极区天空的拱形光弧

极区天空的拱形光弧

ByNASA中文

2021年01月13日 Arches Across an Arctic Sky Image Credit & Copyright: Giulio Cobianchi Explanation: What are these two giant arches across the sky? Perhaps the more familiar one, on the left, is the central band of our Milky Way Galaxy. This grand disk of stars and nebulas here appears to encircle much of the southern sky. Visible below the stellar arch is the rusty-orange planet Mars and the extended Andromeda galaxy. For a few minutes during this cold arctic night, a second giant arch appeared to the right, encircling part of the northern sky: an aurora. Auroras are much closer than stars as they are composed of glowing air high in Earth’s atmosphere. Visible outside the green auroral arch is the group of stars popularly known…

维勾斯峡谷上空的NEOWISE彗星

维勾斯峡谷上空的NEOWISE彗星

ByNASA中文

2020年8月3日 Comet NEOWISE over Vikos Gorge Image Credit & Copyright: Constantine Emmanouilidi Explanation: Did the Earth part to show us this comet? Of course not, even if this image makes it seem that way. Pictured far in the background is Comet NEOWISE as it appeared about two weeks ago over northern Greece. Above the comet are many stars including the bright stars of the Big Dipper (also the Sorcerer, in Aztec mythology), an asterism that many people around the world used to find the naked-eye comet as it hovered in the northern sky over the past month. In the foreground is Vikos Gorge, the deepest gorge on Earth, relative to its width. The gorge was slowly created by erosion from the Voidomatis River over the…

如何找NEOWISE彗星

如何找NEOWISE彗星

ByNASA中文

2020年7月18日 Finding NEOWISE Image Credit & Copyright: Tom Masterson Explanation: If you can see the stars of the Big Dipper, you can find comet NEOWISE in your evening sky tonight. After sunset look for the naked-eye comet below the bowl of the famous celestial kitchen utensil of the north and above your northwestern horizon. You’re looking for a fuzzy ‘star’ with a tail, though probably not so long a tail as in this clear sky snapshot taken from Los Padres National Forest in California on the evening of July 16. Recent photographs of C/2020 F3 (NEOWISE) often show this comet’s broad dust tail and fainter but separate ion tail extending farther than the eye can follow. Skygazers around the world have been delighted to find…

英仙座流星雨与北斗七星

英仙座流星雨与北斗七星

ByNASA中文

2019 August 15 The Perseids and the Plough Image Credit & Copyright: Jeff Dai (TWAN) Explanation: Despite interfering moonlight, many denizens of planet Earth were able to watch this year’s Perseid meteor shower. This pastoral scene includes local skygazers admiring the shower’s brief, heavenly flashes in predawn hours near peak activity on August 13 from Nalati Grassland in Xinjiang, China. A composite, the image registers seven frames taken during a two hour span recording Perseid meteor streaks against a starry sky. Centered along the horizon is the Plough, the north’s most famous asterism, though some might see the familiar celestial kitchen utensil known as the Big Dipper. Perhaps the year’s most easily enjoyed meteor shower, Perseid meteors are produced as Earth itself sweeps through dust…