2024年02月26日:火星卫星之间的交食-（Martian Moon Eclipses Martian Moon） 2024年02月26日:火星卫星之间的交食-（Martian Moon Eclipses Martian Moon）--原图下载2024 February 26 <iframe width="960" height="540"src="https://youtube.com/embed/hwQTH0IGrwE?rel=0"title="YouTube video player"frameborder="0"allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share"allowfullscreen>{mtitle title="火星卫星之间的交食"/}Video Credit: ESA, DLR, FU Berlin, Mars Express;Processing & CC BY 2.0 License:Andrea Luck说明: 如果天空中的2颗卫星发生了交食，那么它们所形成的景观何似？火星还真的出现了这种景观。这部主题影片，呈现了记录这例特殊交食事件的版本之一。而影像的主角分别是火星的2颗卫星：位于较密近轨道、个头也较大的火卫一，以及位于较外围轨道、较娇小的火卫二。这个影像序列，是由欧洲航天局绕行火星的特快车号太空船摄于去年。在火星表面也可以见到类似的交食景观，只是很罕见。从火星表面看出去，较密近的火卫一看似掠过较远的火卫二前方。由于这两颗卫星的轨道非常接近火星，因此很奇特的是，它们会西升东落，它们运动的方向与月亮完全相反。较接近火星的火卫一，轨道非常密近且速度非常快，每天大约会掠过头顶3次。{lamp/}原文：{mtitle title="Martian Moon Eclipses Martian Moon"/}Video Credit: ESA, DLR, FU Berlin, Mars Express;Processing & CC BY 2.0 License:Andrea LuckExplanation: What if there were two moons in the sky -- and they eclipsed each other?This happens on Mars.The featured video shows a version of this unusual eclipse from space.Pictured are the two moons of Mars: the larger Phobos, which orbits closer to the red planet, and the smaller Deimos, which orbits further out.The sequence was captured last year by the ESA’s Mars Express, a robotic spacecraft that itself orbits Mars.A similar eclipse is visible from the Martian surface, although very rarely. From the surface, though, the closer moon Phobos would appear to pass in front of farther moon Deimos.Most oddly, both moons orbit Mars so close that they appear to move backwards when compared to Earth's Moon from Earth, both rising in west and setting in the east.Phobos, the closer moon, orbits so close and so fast that it passes nearly overhead about three times a day.

2023年12月12日:挪威上空的极光与银河-（Aurora and Milky Way over Norway） [2023年12月12日:挪威上空的极光与银河-（Aurora and Milky Way over Norway）--原图下载](https://apod.nasa.gov/apod/image/2312/ArcticNight_Cobianchi_2048.jpg"onMouseOver="if (document.images)document.imagename1.src='image/2312/ArcticNight_Cobianchi_1080_annotated.jpg';"onMouseOut="if (document.images)document.imagename1.src='image/2312/ArcticNight_Cobianchi_1080.jpg';){mtitle title="挪威上空的极光与银河"/}Image Credit & Copyright: Giulio Cobianchi说明: 天空中这二道庞大的拱形光弧是什么？左侧是我们较熟悉的银河系中央盘面；它是由众多银盘恒星和星云汇集而成，在影像里看似几乎环绕整个南天的光带。银河拱的下方，则有鏽红色的火星和弥漫的仙女大星系。然而这个酷寒的极区夜晚另有其他精采之处。在短短的数分钟期间，由极光聚成、伸展在北天的複层拱形光弧，突然出现在影像右侧。很显然的，地球大气高层的极光，远比恒星要邻近。在泛绿的极光拱弧上方，则可见到构成北斗七星的一群恒星。这幅主题影像，组合自2022年11月中旬摄于挪威．罗弗敦群岛的20张照片。{lamp/}原文：{mtitle title="Aurora and Milky Way over Norway"/}Image Credit & Copyright: Giulio CobianchiExplanation: 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.But this night had more! For a few minutes during this coldarctic night, a second giant arch appeared 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 as the Big Dipper. The featured digital composite of 20 images was captured in mid-November 2022 over the Lofoten Islands in Norway.

2023年11月07日:旋掠而过的火星尘暴-（A Martian Dust Devil Spins By） 2023年11月07日:旋掠而过的火星尘暴-（A Martian Dust Devil Spins By）--原图下载2023 November 7 {mtitle title="旋掠而过的火星尘暴"/}Video Credit: NASA,JPL-Caltech, Perseverance Rover;AI processing: PipploIMP说明: 它在火星表面移动，然而它是什么？ 尘捲风。这种受温暖表面加热而旋转上升的气柱，在地球热且乾燥的地区也很常见。尘捲风通常只持续几分钟，当它们捲起鬆散的红色沙尘时才会现形，而下面颜色较深且较重的沙粒则完好无损。尘捲风不仅看起来很酷，它们还会留下鲜明的足痕，并曾意外的清扫了太阳能板的表面。这部经由人工智慧内插的主题影片，所根植的影像，是由目前在耶杰罗坑内寻找远古生命迹证的毅力号火星车，摄于今年8月初。这部长6秒钟的缩时影片，所压缩的实际期间超过1分钟。出现在这片视野远处的尘捲风，估计以每小时约20公里的速度飞掠，并垂直伸展了约2公里高。{lamp/}原文：{mtitle title="A Martian Dust Devil Spins By"/}Video Credit: NASA,JPL-Caltech, Perseverance Rover;AI processing: PipploIMPExplanation: It moved across the surface of Mars -- what was it?A dust devil.Such spinning columns of rising air are heated by the warm surface and are also common in warm and dry areas on planet Earth. Typically lasting only a few minutes, dust devils become visible as they pick up loose red-colored dust, leaving the darker and heavier sand beneath intact. Dust devils not only look cool -- they can leave visible trails, and have been credited with unexpected cleanings of the surfaces of solar panels.The images in the featured AI-interpolated video were captured in early August by the Perseverance rover currently searching for signs of ancient life in Jezero Crater.The six-second time-lapse video encapsulates a real duration of just over one minute. Visible in the distance, the spinning dust devil was estimated to be passingby at about 20 kilometers per hour and extend up about 2 kilometers high.

2023年07月31日:火星上空的火卫一-（Phobos over Mars） 2023年07月31日:火星上空的火卫一-（Phobos over Mars）--原图下载{mtitle title="火星上空的火卫一"/}Image Credit: ESA, DLR, FU Berlin, Mars Express;Processing & CC BY 2.0 License:Andrea Luck说明: 火卫一为何如此黝黑？火卫一是火星的两颗卫星之中，最大和最接近火星的那颗，同时也是整个太阳系里最黝黑的卫星。它不寻常的轨道与色泽，显示火卫一可能是被火星所俘获、组成混杂了冰晶与黑色石头的小行星。这幅火卫一悬在火星临边附近的人为上色主题影像，是由目前在绕行火星的欧洲航天局．火星特快车号摄于2021年。火卫一是颗荒芜满布陨石坑的卫星，它最大的撞击坑位于反面。分析包括此图在内的这类影像，科学家推断火卫一表面可能有一层厚达1公尺的粉尘。由于火卫一的轨道极为靠近火星，因此部分地区一天能看到火卫一发生二次升落，也有部分地区则是一次也没见到。火卫一的轨道不停衰减，大约在5千万年内，就会崩解并撞到火星表面上。{lamp/}原文：{mtitle title="Phobos over Mars"/}Image Credit: ESA, DLR, FU Berlin, Mars Express;Processing & CC BY 2.0 License:Andrea LuckExplanation: Why is Phobos so dark? Phobos, the largest and innermost of the twoMartian moons, is the darkest moon in the entire Solar System. Its unusual orbit and color indicate that it may be a captured asteroid composed of a mixture of ice and dark rock. The featured assigned-color picture of Phobos near the edge of Mars was captured in late 2021 by ESA's robot spacecraft Mars Express, currently orbiting Mars. Phobos is a heavily cratered and barren moon, with its largest crater located on the far side. From images like this, Phobos has been determined to be covered by perhaps a meter of loose dust. Phobos orbits so close to Mars that from some places it would appear to rise and set twice a day, while from other places it would not be visible at all. Phobos' orbit around Mars is continually decaying -- it will likely break up with pieces crashing to the Martian surface in about 50 million years.

2023年06月25日:木星的闪电-（Lightning on Jupiter） 2023年06月25日:木星的闪电-（Lightning on Jupiter）--原图下载{mtitle title="木星的闪电"/}Image Credit: NASA/JPL-Caltech/SwRI/MSSS;Processing & License:Kevin M. Gill说明: 地球是唯一有闪电的行星吗？不是。探索太阳系的多艘太空船，已在火星、木星及土星等行星侦测到闪电，此外，金星、天王星及海王星可能也有闪电。闪电是带电粒子在二个区域之间急遽流动所产生的现象。在地球上，一波波有互撞冰粒及小水滴的涌升流，通常是造成电荷分离进而产生闪电的关键，然而，木星的闪电是怎么来的？绕行木星的朱诺号太空船的所取得的影像和数据，进一步支持木星的闪电亦是由含水及冰的云所产生的之揣测。在这幅由朱诺号所拍摄的主题照片里，可看到出现在木星北极大涡旋云的光学亮闪。在接下来的数个月里，朱诺号将进行数次木星夜面的近距离飞越，届时朱诺号或许可取得更多木星的闪电数据与影像。{lamp/}原文：{mtitle title="Lightning on Jupiter"/}Image Credit: NASA/JPL-Caltech/SwRI/MSSS;Processing & License:Kevin M. GillExplanation: Does lightning occur only on Earth? No. Spacecraft in our Solar System have detected lightning on other planets, including Mars, Jupiter and Saturn, and lightning is likely on Venus,Uranus, and Neptune. Lightning is a sudden rush of electrically charged particles from one location to another.On Earth, drafts of colliding ice and water droplets usually create lightning-generating charge separation, but what happens on Jupiter?Images and data from NASA's Jupiter-orbiting Juno spacecraft bolster previous speculation that Jovian lightning is also created in clouds containing water and ice. In the featured Juno photograph, an optical flash was captured in a large cloud vortex near Jupiter's north pole. During the next few months, Juno will perform several close sweeps over Jupiter's night side, likely allowing the robotic probe to capture more data and images of Jovian lightning.

2023年05月02日:火星的平顶岩丘-（Flat Rock Hills on Mars） 2023年05月02日:火星的平顶岩丘-（Flat Rock Hills on Mars）--原图下载{mtitle title="火星的平顶岩丘"/}Image Credit & Copyright: NASA, JPL-Caltech, MSSS;Processing: Neville Thompson说明: 为何火星有这么多平顶的岩石？相对于地球上的岩石，火星的一些平原和丘陵看似拥有许多格外平坦的石块。造成这种景观的原因之一，是火星和地球都共有的侵蚀作用过程。以二氧化碳为主体的火星风所挟带的火星沙砾，发挥了像砂纸一样的作用，而这些沙砾可造成差异侵蚀，让部分岩石变得光滑，也磨平了其他长期暴露岩块的顶部。这幅由美国航太总署好奇号火星车摄于上个月的主题影像，就记录了数座覆着平顶岩的山丘。这部火星车已经在火星表面漫游了10年，并为釐清地球这颗行星近邻的潮湿和多风的历史细节提供了许多助力。在拍下这幅及其他影像之后，好奇号小心翼翼的绕过岩块和滑溜的沙地，然后爬上了标誌环谷（Marker Band Valley）。{lamp/}原文：{mtitle title="Flat Rock Hills on Mars"/}Image Credit & Copyright: NASA, JPL-Caltech, MSSS;Processing: Neville ThompsonExplanation: Why are there so many flat rocks on Mars?Some views of plains and hills on Mars show many rocks that are unusually flat when compared to rocks on Earth.One reason for this is a process that is common to both Mars and Earth: erosion.The carbon-dioxide wind on Mars can act like sandpaper when it blows around gritty Martian sand.This sand can create differential erosion, smoothing over some rocks, while wearing down the tops of other long-exposed stones. The featured image capturing several hills covered with flat-topped rocks was taken last month by NASA's Curiosity Rover on Mars.This robotic rover has now been rolling across Mars for ten years and has helped uncover many details of the wet and windy past of Earth's planetary neighbor. After taking this and other images, Curiosity carefully navigated stones and slippery sand to climb up Marker Band Valley.