木卫二

木卫二

ByNASA中文

2022年1月15日 Galileo’s Europa Image Credit: NASA, JPL-Caltech, SETI Institute, Cynthia Phillips, Marty Valenti Explanation: Looping through the Jovian system in the late 1990s, the Galileo spacecraft recorded stunning views of Europa and uncovered evidence that the moon’s icy surface likely hides a deep, global ocean. Galileo’s Europa image data has been remastered here, with improved calibrations to produce a color image approximating what the human eye might see. Europa’s long curving fractures hint at the subsurface liquid water. The tidal flexing the large moon experiences in its elliptical orbit around Jupiter supplies the energy to keep the ocean liquid. But more tantalizing is the possibility that even in the absence of sunlight that process could also supply the energy to support life, making Europa one…

NGC 1566：西班牙舞者螺旋星系

NGC 1566：西班牙舞者螺旋星系

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2022年1月14日 NGC 1566: The Spanish Dancer Spiral Galaxy Image Credit & Copyright: Mark Hanson and Mike Selby Explanation: An island universe of billions of stars, NGC 1566 lies about 60 million light-years away in the southern constellation Dorado. Popularly known as the Spanish Dancer galaxy, it’s seen face-on from our Milky Way perspective. A gorgeous grand design spiral, this galaxy’s two graceful spiral arms span over 100,000 light-years, traced by bright blue star clusters, pinkish starforming regions, and swirling cosmic dust lanes. NGC 1566’s flaring center makes the spiral one of the closest and brightest Seyfert galaxies. It likely houses a central supermassive black hole wreaking havoc on surrounding stars, gas, and dust. In this sharp southern galaxy portrait, the spiky stars lie well within…

超新星遗迹Simeis 147

超新星遗迹Simeis 147

ByNASA中文

2022年1月13日 Supernova Remnant Simeis 147 Image Credit & Copyright: Jason Dain Explanation: It’s easy to get lost following the intricate, looping, twisting filaments in this detailed image of supernova remnant Simeis 147. Also cataloged as Sharpless 2-240 it goes by the popular nickname, the Spaghetti Nebula. Seen toward the boundary of the constellations Taurus and Auriga, it covers nearly 3 degrees or 6 full moons on the sky. That’s about 150 light-years at the stellar debris cloud’s estimated distance of 3,000 light-years. This composite includes image data taken through narrow-band filters where reddish emission from ionized hydrogen atoms and doubly ionized oxygen atoms in faint blue-green hues trace the shocked, glowing gas. The supernova remnant has an estimated age of about 40,000 years, meaning light…

猎户腰带区的气体和尘埃

猎户腰带区的气体和尘埃

ByNASA中文

2022年1月11日 Orion’s Belt Region in Gas and Dust Image Credit & Copyright: Matt Harbison (Space4Everybody), Marathon Remote Imaging Observatory Explanation: You may have seen Orion’s belt before — but not like this. The three bright stars across this image are, from left to right, Mintaka, Alnilam, and Alnitak: the iconic belt stars of Orion. The rest of the stars in the frame have been digitally removed to highlight the surrounding clouds of glowing gas and dark dust. Some of these clouds have intriguing shapes, including the Horsehead and Flame Nebulas, both near Alnitak on the lower right. This deep image, taken last month from the Marathon Skypark and Observatory in Marathon, Texas, USA, spans about 5 degrees, required about 20 hours of exposure, and was…

李奥纳德彗星摇摆的彗尾

李奥纳德彗星摇摆的彗尾

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2022年1月10日 Comet Leonard’s Tail Wag Image Credit: NASA, NRL, STEREO-A; Processing: B. Gallagher Explanation: Why does Comet Leonard’s tail wag? The featured time-lapse video shows the ion tail of Comet C/2021 A1 (Leonard) as it changed over ten days early last month. The video was taken by NASA’s Solar Terrestrial Relations Observatory-Ahead (STEREO-A) spacecraft that co-orbits the Sun at roughly the same distance as the Earth. Each image in this 29-degree field was subtracted from following image to create frames that highlight differences. The video clearly shows Comet Leonard’s long ion tail extending, wagging, and otherwise being blown around by the solar wind — a stream of fast-moving ions that stream out from the Sun. Since the video was taken, Comet Leonard continued plunging toward…

哈勃望远镜的木星和缩小的大红斑

哈勃望远镜的木星和缩小的大红斑

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2022年1月9日 Hubble’s Jupiter and the Shrinking Great Red Spot Image Credit: NASA, ESA, Hubble, OPAL Program, STScI; Processing: Karol Masztalerz Explanation: What will become of Jupiter’s Great Red Spot? Gas giant Jupiter is the solar system’s largest world with about 320 times the mass of planet Earth. Jupiter is home to one of the largest and longest lasting storm systems known, the Great Red Spot (GRS), visible to the left. The GRS is so large it could swallow Earth, although it has been shrinking. Comparison with historical notes indicate that the storm spans only about one third of the exposed surface area it had 150 years ago. NASA’s Outer Planets Atmospheres Legacy (OPAL) program has been monitoring the storm more recently using the Hubble Space…

北半球的四分仪座流星雨

北半球的四分仪座流星雨

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2022年1月8日 Quadrantids of the North Image Credit & Copyright: Cheng Luo Explanation: Named for a forgotten constellation, the Quadrantid Meteor Shower puts on an annual show for planet Earth’s northern hemisphere skygazers. The shower’s radiant on the sky lies within the old, astronomically obsolete constellation Quadrans Muralis. That location is not far from the Big Dipper, at the boundaries of the modern constellations Bootes and Draco. In fact north star Polaris is just below center in this frame and the Big Dipper asterism (known to some as the Plough) is above it, with the meteor shower radiant to the right. Pointing back toward the radiant, Quadrantid meteors streak through the night in the panoramic skyscape, a composite of images taken in the hours around the…

日食的狂喜

日食的狂喜

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2022年1月7日 Ecstatic Solar Eclipse Image Credit & Copyright: Annie Schmidt (Point Blue Conservation Science) Explanation: A male Adelie penguin performed this Ecstatic Vocalization in silhouette during the December 4 solar eclipse, the final eclipse of 2021. Of course his Ecstatic Vocalization is a special display that male penguins use to claim their territory and advertise their condition. This penguin’s territory, at Cape Crozier Antarctica, is located in one of the largest Adelie penguin colonies. The colony has been studied by researchers for over 25 years. From there, last December’s eclipse was about 80 percent total when seen at its maximum phase as the Moon’s shadow crossed planet Earth’s southernmost continent. Status Updates: Deploying the James Webb Space Telescope Tomorrow’s picture: forgotten constellation 日食的狂喜 影像提供与版权: Annie…

即将卸任昏星的金星

即将卸任昏星的金星

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2022年1月6日 The Last Days of Venus as the Evening Star Image Credit & Copyright: Tamas Ladanyi (TWAN) Explanation: That’s not a young crescent Moon posing behind cathedral towers after sunset. It’s Venus in a crescent phase. About 40 million kilometers away and about 2 percent illuminated by sunlight, it was captured with camera and telephoto lens in this series of exposures as it set in western skies on January 1 from Veszprem, Hungary. The bright celestial beacon was languishing in the evening twilight, its days as the Evening Star coming to a close as 2022 began. But it was also growing larger in apparent size and becoming an ever thinner crescent in telescopic views. Heading toward a (non-judgemental) inferior conjunction, the inner planet will be…

一年份的日出

一年份的日出

ByNASA中文

2022年1月5日 A Year of Sunrises Image Credit & Copyright: Luca Vanzella 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 2021 as seen from the city of Edmonton, Alberta, Canada. The camera in the image is always facing due east, with north toward the left and south toward the right. As shown in an accompanying video, the top image was taken in 2020 December, while the bottom image was captured in 2021 December, making 13 images in total. Although the Sun always rises in the east in general, it rises furthest to the south of east on the December solstice,…