我们要出发了：阿尔忒弥斯一号在发射台上

我们要出发了：阿尔忒弥斯一号在发射台上

ByNASA中文

NASA’s Space Launch System (SLS) rocket with the Orion spacecraft aboard is seen atop the mobile launcher as it is rolled up the ramp at Launch Pad 39B, Wednesday, Aug. 17, 2022, at NASA’s Kennedy Space Center in Florida. NASA’s Artemis I mission is the first integrated test of the agency’s deep space exploration systems: the Orion spacecraft, SLS rocket, and supporting ground systems. Launch of the uncrewed flight test is targeted for Aug. 29 at the earliest. See this and even more photos on Flickr. Image Credit: NASA/Joel Kowsky 2022年8月17日，星期三，在佛罗里达州的NASA肯尼迪航天中心，NASA的空间发射系统（SLS）火箭与猎户座飞船一起在移动式发射器的顶部缓缓升上到了发射台39B的斜坡。NASA的阿尔忒弥斯一号任务是该机构深空探测系统的首次综合测试：猎户座飞船、SLS火箭和地面支持系统。无人飞行试验最早将于8月29日进行。 在Flickr上查看更多的照片。 影像来源：NASA/Joel Kowsky

形似恒星之门的银河

形似恒星之门的银河

ByNASA中文

2022年8月17日 Stargate Milky Way Image Credit & Copyright: Maxime Oudoux Explanation: There is a huge gate of stars in the sky, and you pass through it twice a day. The stargate is actually our Milky Way Galaxy, and it is the spin of the Earth that appears to propel you through it. More typically, the central band of our Milky Way appears as a faint band stretching across the sky, only visible in away from bright city lights. In a long-exposure wide-angle image from a dark location like this, though, the Milky Way’s central plane is easily visible. The featured picture is a digital composite involving multiple exposures taken on the same night and with the same camera, but employing a stereographic projection that causes…

年度英仙座流星雨

年度英仙座流星雨

ByNASA中文

The Perseid meteors are an annual event many skywatchers look forward to, as they often produce lots of shooting stars to enjoy. The Perseids are debris remnants of Comet Swift-Tuttle, which takes 133 years to orbit the Sun once. The meteors often leave long “wakes” of light and color behind them as they streak through Earth’s atmosphere. They’re also known for their fireballs, which are larger explosions of light and color that can persist longer than an average meteor streak. This photo was taken Wednesday, Aug. 11, 2021, in Spruce Knob, West Virginia. Credit: NASA/Bill Ingalls 英仙座流星雨是许多天文观测者期待的年度活动，因为它们经常会产生许多流星供观赏。英仙座流星雨是斯威夫特-塔特尔彗星的残骸，它绕太阳一周需要133年。流星在穿越地球大气层时，往往会留下长长的光和颜色“尾迹”。它们还以火球而闻名，火球是一种更大的光和颜色爆炸，比流星痕平均持续时间更长。 这张照片于2021年8月11日星期三在西弗吉尼亚州的云杉岭（Spruce Knob）拍摄。 影像来源：NASA/Bill Ingalls

突尼斯上空的流星雨

突尼斯上空的流星雨

ByNASA中文

2022年8月16日 A Meteor Wind over Tunisia Image Credit & Copyright: Makrem Larnaout Explanation: Does the Earth ever pass through a wind of meteors? Yes, and they are frequently visible as meteor showers. Almost all meteors are sand-sized debris that escaped from a Sun-orbiting comet or asteroid, debris that continues in an elongated orbit around the Sun. Circling the same Sun, our Earth can move through an orbiting debris stream, where it can appear, over time, as a meteor wind. The meteors that light up in Earth’s atmosphere, however, are usually destroyed. Their streaks, though, can all be traced back to a single point on the sky called the radiant. The featured image composite was taken over two days in late July near the ancient Berber…

哈勃望远镜看到红色超巨星参宿四在爆炸后缓慢恢复

哈勃望远镜看到红色超巨星参宿四在爆炸后缓慢恢复

ByNASA中文

通过分析来自NASA哈勃太空望远镜和其他几个天文台的数据，天文学家得出结论，明亮的红色超巨星参宿四在2019年发生爆炸，失去了大部分可见表面，并产生了巨大的表面物质抛射（SME）。这是在正常恒星的行为中从未见过的现象。 我们的太阳通常会抛射出其稀薄的外层大气日冕的一部分，这被称为日冕物质抛射（CME）。但是参宿四SME爆炸的质量是典型CME的4,000亿倍！ 这颗巨型恒星仍在缓慢地从这场灾难性的剧变中恢复。“参宿四现在仍在做一些非常不寻常的事情；它的内部有点反弹。”马萨诸塞州剑桥哈佛和史密森天体物理中心的安德里亚·杜普利说。 这些新的观测结果提供了一些线索，让我们了解到红色恒星在其核聚变熔炉烧尽后，在爆炸成为超新星之前，是如何在生命后期失去质量。质量损失的数量显著影响它们的命运。然而，参宿四出人意料的暴躁行为并不是该恒星即将爆炸的证据。因此，质量损失事件不一定是即将发生爆炸的信号。 杜普瑞现在正在把这颗恒星在喷发前、喷发后和喷发期间的任性行为的所有谜团拼凑起来，形成一个连贯的故事，讲述一颗衰老恒星中前所未见的巨大变动。 这幅图描绘了红色超巨星参宿四在一大块可见表面发生巨大质量抛射后亮度的变化。从地球上看，抛射出来的物质冷却后形成一团尘埃，暂时使恒星看起来更暗。这场史无前例的恒星剧变破坏了这颗巨星长达400天的振荡周期，天文学家已经测量了200多年。现在，内部可能会像一盘明胶甜点一样摇晃。 影像来源：NASA, ESA, Elizabeth Wheatley (STScI) 这包括来自STELLA机器人天文台、弗雷德·劳伦斯·惠普尔天文台的蒂林赫斯特反射式阶梯摄谱仪（Tillinghast Reflector Echelle Spectrograph, TRES）、NASA的日地关系天文台（STEREO-A）、NASA的哈勃空间望远镜和美国变星观察员协会（AAVSO）的新光谱和成像数据。杜普利强调，哈勃的数据对解开谜团至关重要。 “我们以前从未见过恒星表面发生巨大的物质抛射。我们还没有完全理解正在发生的事情。这是一种全新的现象，我们可以用哈勃直接观察并解析表面细节。我们正在实时观察恒星的演化。” 2019年参宿四的巨大爆发可能是由一股直径超过100万英里的对流羽流引起的，它从恒星内部深处冒出来。它产生的冲击和脉动，将光球层的一部分炸开，使恒星在由光球层的冷却部分产生的尘埃云下有很大的冷却表面积。参宿四现在正努力从这一损伤中恢复。 这片破碎的光球碎片重量大约是月球的几倍，它迅速飞入太空，冷却后形成尘埃云，阻挡了地球观测者看到的恒星发出的光线。这种变暗现象始于2019年底，持续了几个月，即使是在后院观察恒星亮度变化的观察者也很容易注意到。参宿四是天空中最亮的恒星之一，很容易在猎户座的右肩找到。 更神奇的是，这颗超级巨星400天的脉动频率现在已经消失了，也许至少暂时消失了。近200年来，天文学家们一直在测量参宿四这个节奏明显的亮度变化和表面运动变化。它的破坏证明了喷发的凶猛。 杜普利认为，这颗恒星内部的对流室驱动有规律的脉动，可能像不平衡的洗衣机浴缸一样四处晃动。TRES和哈勃光谱暗示外层可能会恢复正常，但在光球层重建的过程中，表面仍然像一盘明胶甜点一样弹跳。 尽管我们的太阳有日冕物质抛射，会抛射外层大气的一小部分，但天文学家从未见过如此大量的恒星可见表面被喷射到太空中。因此，表面物质抛射和日冕物质抛射可能是不同的事件。 参宿四现在非常巨大，如果它取代了太阳系中心的太阳，它的外表面将延伸超过木星的轨道。1996年，杜普利利用哈勃望远镜分辨出恒星表面的热点。这是除太阳外的第一张恒星的直接图像。 NASA的韦伯太空望远镜可可能能够探测到不断远离恒星的红外光喷射物质。 哈勃太空望远镜是NASA和ESA（欧洲航天局）之间的国际合作项目。位于马里兰州绿带的美国宇航局戈达德航天飞行中心负责管理该望远镜。位于马里兰州巴尔的摩的空间望远镜科学研究所（STScI）负责哈勃的科学操作。STScI由位于华盛顿特区的天文学研究大学协会为NASA运营。 参考来源： https://www.nasa.gov/feature/goddard/2022/hubble-sees-red-supergiant-star-betelgeuse-slowly-recovering-after-blowing-its-top

Aquanaut机器人在水下工作

Aquanaut机器人在水下工作

ByNASA中文

A team of roboticists from NASA’s Johnson Space Center in Houston have applied their expertise in making robots for deep space to designing a fully electric shape-changing submersible robot that will cut costs for maritime industries. Aquanaut, seen here during testing in the giant pool at Johnson’s Neutral Buoyancy Lab, opens its shell and turns its arms, claw hands, and various sensors to the job. NASA has a long history of transferring technology to the private sector. The agency’s Spinoff publication profiles NASA technologies that have transformed into commercial products and services, demonstrating the broader benefits of America’s investment in its space program. Spinoff is a publication of the Technology Transfer program in NASA’s Space Technology Mission Directorate (STMD). Learn more: NASA Space Robotics Dive…

天鹅座的恒星诞生之墙

天鹅座的恒星诞生之墙

ByNASA中文

2022年8月15日 The Cygnus Wall of Star Formation Image Credit & Copyright: Johan Bogaerts Explanation: The North America nebula on the sky can do what the North America continent on Earth cannot — form stars. Specifically, in analogy to the Earth-confined continent, the bright part that appears as Central America and Mexico is actually a hot bed of gas, dust, and newly formed stars known as the Cygnus Wall. The featured image shows the star forming wall lit and eroded by bright young stars, and partly hidden by the dark dust they have created. The part of the North America nebula (NGC 7000) shown spans about 15 light years and lies about 1,500 light years away toward the constellation of the Swan (Cygnus). Tomorrow’s picture: meteor…

4000颗系外行星

4000颗系外行星

ByNASA中文

2022年8月14日 4000 Exoplanets Video Credit: SYSTEM Sounds (M. Russo, A. Santaguida); Data: NASA Exoplanet Archive Explanation: Over 4000 planets are now known to exist outside our Solar System. Known as exoplanets, this milestone was passed last month, as recorded by NASA’s Exoplanet Archive. The featured video highlights these exoplanets in sound and light, starting chronologically from the first confirmed detection in 1992 and continuing into 2019. The entire night sky is first shown compressed with the central band of our Milky Way Galaxy making a giant U. Exoplanets detected by slight jiggles in their parents-star’s colors (radial velocity) appear in pink, while those detected by slight dips in their parent star’s brightness (transit) are shown in purple. Further, those exoplanets imaged directly appear in orange,…

土卫一的赫歇尔陨石坑

土卫一的赫歇尔陨石坑

ByNASA中文

2022年8月13日 Herschel Crater on Mimas Image Credit Cassini Imaging Team, ISS, JPL, ESA, NASA Explanation: Mimas, small 400 kilometer-diameter moon of Saturn, is host to 130 kilometer-diameter Herschel crater, one of the larger impact craters in the entire Solar System. The robotic Cassini spacecraft orbiting Saturn in 2010 recorded this startling view of small moon and big crater while making a 10,000-kilometer record close pass by the diminutive icy world. Shown in contrast-enhanced false color, the image data reveal more clearly that Herschel’s landscape is colored slightly differently from heavily cratered terrain nearby. The color difference could yield surface composition clues to the violent history of Mimas. Of course, an impact on Mimas any larger than the one that created the 130-kilometer Herschel might have…

哈勃望远镜俯瞰着太空的云景

哈勃望远镜俯瞰着太空的云景

ByNASA中文

This celestial cloudscape from the NASA/ESA Hubble Space Telescope captures the colorful region in the Orion Nebula surrounding the Herbig-Haro object HH 505. Herbig-Haro objects are luminous regions surrounding newborn stars that form when stellar winds or jets of gas spew from these infant stars creating shockwaves that collide with nearby gas and dust at high speeds. In the case of HH 505, these outflows originate from the star IX Ori, which lies on the outskirts of the Orion Nebula around 1,000 light-years from Earth. The outflows themselves are visible as gracefully curving structures at the top and bottom of this image. Their interaction with the large-scale flow of gas and dust from the core of the nebula distorts them into sinuous curves. Captured with…