昴宿星团：七姐妹星团

昴宿星团：七姐妹星团

ByNASA中文

2021年11月24日 Pleiades: The Seven Sisters Star Cluster Image Credit & Copyright: Damien Cannane Explanation: Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as large and clear as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen without binoculars from even the depths of a light-polluted city. With a long exposure from a dark location, though, the dust cloud surrounding the Pleiades star cluster becomes very evident. The featured exposure, taken from Florida, USA, covers a sky area several times the size of the full moon. Also known as the Seven Sisters and M45, the Pleiades lies about 400 light years away toward the constellation of…

敬请关注DART！

敬请关注DART！

ByNASA中文

The Double Asteroid Redirection Test (DART), which will help determine if intentionally crashing a spacecraft into an asteroid is an effective way to change its course, is scheduled to launch no earlier than 1:21 a.m. EST Wednesday, Nov. 24 (10:21 p.m. PST Tuesday, Nov. 23) on a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California. 双重小行星重定向测试（DART）将有助于确定故意将航天器撞向小行星是否是改变其轨道的有效方式，该测试计划不早于美国东部时间11月24日星期三凌晨1:21（北京时间11月23日星期二晚上10:21），由SpaceX猎鹰9号火箭从加利福尼亚州范登堡空军基地发射。 This illustration is of the DART spacecraft and the Italian Space Agency’s (ASI) LICIACube prior to impact at the Didymos binary system. 这张插图是DART航天器和意大利航天局（ASI）的LICIACube在撞击Didymos双星系统之前的示意图。 DART is the agency’s first planetary defense test mission and the target asteroid is not a threat to Earth. DART是NASA的第一个行星防御测试任务，目标小行星对地球不构成威胁。 Learn more about social media and other activities for the mission. 了解更多关于该任务的社交媒体和其他活动。 Image Credits: NASA/Johns Hopkins, APL/Steve Gribben 图片来源: NASA/Johns Hopkins, APL/Steve Gribben

核分光望远镜拍摄的X波段太阳

核分光望远镜拍摄的X波段太阳

ByNASA中文

2021年11月23日 The Sun in X-rays from NuSTAR Image Credit: NASA, NuSTAR, SDO Explanation: Why are the regions above sunspots so hot? Sunspots themselves are a bit cooler than the surrounding solar surface because the magnetic fields that create them reduce convective heating. It is therefore unusual that regions overhead — even much higher up in the Sun’s corona — can be hundreds of times hotter. To help find the cause, NASA directed the Earth-orbiting Nuclear Spectroscopic Telescope Array (NuSTAR) satellite to point its very sensitive X-ray telescope at the Sun. Featured here is the Sun in ultraviolet light, shown in a red hue as taken by the orbiting Solar Dynamics Observatory (SDO). Superimposed in false-colored green and blue is emission above sunspots detected by NuSTAR…

哈勃发现火焰星云中的尘埃漩涡

哈勃发现火焰星云中的尘埃漩涡

ByNASA中文

The Flame Nebula, also called NGC 2024, is a large star-forming region in the constellation Orion that lies about 1,400 light-years from Earth. It’s a portion of the Orion Molecular Cloud Complex, which includes such famous nebulae as the Horsehead Nebula and Orion Nebula. This image focuses on the dark, dusty heart of the nebula, where a star cluster resides, mostly hidden from view. Nearby (but not visible in this image) is the bright star Alnitak, the easternmost star in the Belt of Orion. Radiation from Alnitak ionizes the Flame Nebula’s hydrogen gas. As the gas begins to cool from its higher-energy state to a lower-energy state, it emits energy in the form of light, causing the visible glow behind the swirled wisps of dust….

摩天大楼上方的食月

摩天大楼上方的食月

ByNASA中文

2021年11月22日 Lunar Eclipse over a Skyscraper Image Credit & Copyright: Yuri Beletsky (Carnegie Las Campanas Observatory, TWAN) Explanation: Why is the Moon on top of this building? Planning. It took the astrophotographer careful planning — including figuring out exactly where to place the camera and exactly when to take the shot — to create this striking superposition. The single image featured was taken in the early morning hours of November 19, near the peak of the partial lunar eclipse that was occurring as the Moon passed through the Earth’s shadow. At this time, almost the entire Moon — 99.1 percent of its area — was in the darkest part of the Earth’s shadow. The building is the Gran Torre Santiago building in Chile, the tallest…

伦纳德彗星

伦纳德彗星

ByNASA中文

2021年11月21日 Introducing Comet Leonard Image Credit & Copyright: Dan Bartlett Explanation: Here comes Comet Leonard. Comet C/2021 A1 (Leonard) was discovered as a faint smudge in January 2021 when it was out past Mars — but its orbit will take the giant shedding ice-ball into the inner Solar System, passing near both Earth and Venus in December before it swoops around the Sun in early January 2022. Although comets are notoriously hard to predict, some estimations have Comet Leonard brightening to become visible to the unaided eye in December. Comet Leonard was captured just over a week ago already sporting a green-tinged coma and an extended dust tail. The featured picture was composed from 62 images taken through a moderate-sized telescope — one set of…

近乎月全食

近乎月全食

ByNASA中文

2021年11月20日 An Almost Total Lunar Eclipse Image Credit & Copyright: Robert Fedez Explanation: Predawn hours of November 19 found the Moon in partly cloudy skies over Cancun, Mexico. Captured in this telephoto snapshot, the lunar disk is not quite entirely immersed in Earth’s dark umbral shadow during a long partial lunar eclipse. The partial eclipse was deep though, deep enough to show the dimmed but reddened light in Earth’s shadow. That’s a sight often anticipated by fans of total lunar eclipses. Wandering through the constellation Taurus, the eclipsed Moon’s dimmer light also made it easier to spot the Pleiades star cluster. The stars of the Seven Sisters share this frame at the upper right, with the almost totally eclipsed Moon. Notable APOD Submissions (so far):…

Crew-1宇航员维克多·格洛弗与华盛顿特区的学生见面

Crew-1宇航员维克多·格洛弗与华盛顿特区的学生见面

ByNASA中文

NASA astronaut Victor Glover speaks with students about his time aboard the International Space Station, Thursday, Nov. 18, 2021, at Ben’s Chili Bowl in Washington. Students from Cardozo Educational Campus, Friendship Technology Preparatory High School, McKinley Technical High School, Phelps High School, and Wilson High School heard NASA astronauts Glover, Mike Hopkins, and Shannon Walker speak about the Crew-1 mission, the first crew rotation mission to the International Space Station. Part of the agency’s Commercial Crew Program, the crew was launched aboard a SpaceX Falcon 9 and Crew Dragon and spent 168 days in space. 2021年11月18日星期四，NASA宇航员维克多·格洛弗在华盛顿的本氏辣椒面馆与学生谈论他在国际空间站上的生活。来自卡多佐教育学院、友谊技术预备高中、麦金利技术高中、菲尔普斯高中和威尔逊高中的学生们听取了美国宇航局宇航员格洛弗、迈克-霍普金斯和香农·沃克关于Crew-1任务的演讲，这是第一次前往国际空间站的机组人员轮换任务。作为NASA商业宇航员计划的一部分，宇航员们乘坐SpaceX的猎鹰9号和载人龙飞船发射升空，在太空中度过了168天。 Image Credit: NASA/Joel Kowsky 图片来源：NASA/Joel Kowsky

NGC 281：移除恒星后再叠合恒星

NGC 281：移除恒星后再叠合恒星

ByNASA中文

2021年11月19日 NGC 281: Starless with Stars Image Credit & Copyright: Wido Oerlemans – X-ray: Chandra, Infrared: Spitzer Explanation: In visible light the stars have been removed from this narrow-band image of NGC 281, a star forming region some 10,000 light-years away toward the constellation Cassiopeia. Stars were digitally added back to the resulting starless image though. But instead of using visible light image data, the stars were added with X-ray data (in purple) from the Chandra X-ray Observatory and infrared data (in red) from the Spitzer Space Telescope. The merged multiwavelength view reveals a multitude of stars in the region’s embedded star cluster IC 1590. The young stars are normally hidden in visible light images by the natal cloud’s gas and obscuring dust. Also known…

毅力号拍摄到火星直升机具有挑战性的飞行

毅力号拍摄到火星直升机具有挑战性的飞行

ByNASA中文

2021年9月4日，NASA毅力号火星车上的Mastcam-Z仪器的视频拍摄到了该机构的机智号火星直升机的第13次飞行的特写镜头。 视频来源：NASA/JPL-Caltech/ASU/MSSS 最近9月飞行的下行图像，让火星车成像团队将一段旋翼飞行器表现近乎完美的视频整合在一起。 NASA毅力号火星车9月4日拍摄的机智号火星直升机第13次飞行的视频，提供了迄今为止最详细的旋翼机的运行情况。 机智号目前正在为其第16次飞行做准备，计划不早于11月20日星期六进行，但160.5秒的第13次飞行是机智号最复杂的飞行之一。它涉及飞入“Séítah”地质特征内的各种地形，并为火星车团队从多个角度拍摄露头的图像。从26英尺（8米）的高度获取的图像，补充了第12次飞行期间收集的图像，为毅力号的科学家和火星车驾驶员提供了宝贵的见解。 由火星车的双摄像头Mastcam-Z拍摄，第13次飞行的一个视频片段显示了4磅（1.8公斤）的旋翼飞机的大部分飞行轮廓。另一个视频提供了起飞和降落的特写镜头，这是一项科学观测的一部分，旨在测量直升机产生的尘埃羽流。 “Mastcam-Z的价值在这些视频剪辑中真正体现出来，”NASA南加州喷气推进实验室Mastcam-Z仪器的副首席研究员贾斯汀·马基说。“即使在300米[328码]之外，我们也能通过Mastcam-Z的‘右眼’拍摄到起飞和降落的精彩特写。虽然在通过‘左眼’拍摄的广角视野中，直升机只是一个小斑点，但它让观众很好地感受到了机智号正在探索的环境的大小。” 在起飞过程中，机智号掀起了一小缕灰尘，右边的相机或 “眼睛 “拍摄到了在上升过程中向直升机右侧移动。在最初爬升到计划的最大高度26英尺（8米）后，直升机会做一个小的自旋动作，将彩色摄像机对准目标。然后，机智号俯冲，让旋翼的推力开始在稀薄的火星空气中水平移动，然后移动到屏幕外。之后，旋翼直升机返回并降落在起飞地点附近。该团队瞄准了一个不同的着陆点——离起飞约39英尺(12米)——以避免在第12次飞行完成时降落在沙地上的涟漪。 2021年9月4日，NASA毅力号火星车上的Mastcam-Z仪器的视频片段提供了机智号火星直升机第13次飞行的全景透视图。 影像来源：NASA/JPL-Caltech/ASU/MSSS 尽管从Mastcam-Z的左眼看去，直升机的画面比右眼少，火星的画面多，但这个广角让人看到了机智号团队为确保飞行成功而进行编程的独特方式。 “我们从陨石坑底部起飞，飞过一条高高的山脊线，然后进入Séítah，”喷气推进实验室的独创性首席飞行员霍华德·格里普说。“由于直升机的导航过滤器更喜欢平坦的地形，我们在山脊线附近编入了一个航点，直升机在那里减速并盘旋片刻。我们的飞行模拟表明，这个小小的’喘息’将帮助直升机在巨大的地形变化中保持其方向。直升机在回去的路上也是这样。能亲眼看到这种情况的发生真是太棒了，它加强了我们建模的准确性和我们对如何最佳操作机智号的理解。” 广角视图也显示了机智号如何在飞行过程中保持高度。在最初上升到26英尺(8米)高度后，直升机向东北方向的山脊线飞行时，激光测高仪记录下了地面高度的变化。机智号会自动调整，在接近山脊时稍微上升，然后下降到比起伏的表面高出26英尺(8米)。一旦它向右飞出视野，机智号就会用它的彩色相机收集10张岩石露头的图像，然后返回到画面中，回到目标位置。 在第13次飞行之后，机智号和NASA的其他火星探测器在10月的火星太阳合相期间安静了下来，那时火星和地球在太阳的两端，阻碍了大多数通信。在合相之后，机智号在进行第15次飞行前进行了一次短暂的实验性飞行测试，开始了返回“莱特兄弟基地”附近的多飞行旅程，这是它在4月份的出发点。 有关机智号的更多信息 机智号火星直升机由喷气推进实验室建造，喷气推进实验室还为NASA总部管理其扩展任务期间的操作演示活动。它得到了美国宇航局科学、航空研究和空间技术任务局的支持。NASA位于加州硅谷的艾姆斯研究中心和位于弗吉尼亚州汉普顿的兰利研究中心在机智号的开发过程中提供了重要的飞行性能分析和技术援助。AeroVironment Inc.、高通和SolAero也提供了设计协助和主要工具组件。洛克希德马丁航天公司设计并制造了火星直升机运送系统。 有关毅力号的更多相关信息 毅力号任务在火星上的主要目标是天体生物学，包括寻找古微生物生命的迹象。毅力号将对火星的地质和过去的气候进行表征，为未来人类探索红色星球铺平道路，除此之外，毅力号任务还是第一个收集和储存火星岩石和风化层样本的任务。 NASA将与欧洲空间局合作进行后续的飞行任务，送探测器前往火星，从火星表面收集暂时缓存的样本，然后将它们返回地球进行进一步的分析。 喷气推进实验室由位于加利福尼亚州帕萨迪纳市的加州理工学院为NASA代为管理，毅力号的建造和运营管理由喷气推进实验室负责。 如欲了解毅力号火星探测任务的更多相关信息，请访问： nasa.gov/perseverance 以及 mars.nasa.gov/mars2020/ 参考来源： https://www.nasa.gov/feature/jpl/nasa-s-perseverance-captures-challenging-flight-by-mars-helicopter