观星指南（2023年7月）
七月的天空会发生什么？火星和金星分道扬镳，土星与一颗充满尘埃的年轻恒星一起巡游，这是观测银河系的黄金时段。
天龙座的三重星系
2023年7月1日 Three Galaxies in Draco Image Credit & Copyright: David Vernet, Jean-François Bax, Serge Brunier, OCA/C2PU Explanation: This tantalizing trio of galaxies sometimes called the Draco Group, is located in the northern constellation of (you guessed it) Draco, the Dragon. From left to right are face-on spiral NGC 5985, elliptical galaxy NGC 5982, and edge-on spiral NGC 5981, all found within this single telescopic field of view that spans a little more than the width of the full moon. While the group is far too small to be a galaxy cluster, and has not been catalogued as a compact galaxy group, the three galaxies all do lie roughly 100 million light-years from planet Earth. Not as well known as other tight groupings of galaxies, the…
可能会祸害地球的小行星之轨道
2023年6月30日 Orbits of Potentially Hazardous Asteroids Illustration Credit: NASA, JPL-Caltech Explanation: Are asteroids dangerous? Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low. Because some past mass extinction events have been linked to asteroid impacts, however, humanity has made it a priority to find and catalog those asteroids that may one day affect life on Earth. Pictured here are the orbits of the over 1,000 known Potentially Hazardous Asteroids (PHAs). These documented tumbling boulders of rock and ice are over 140 meters across and will pass within 7.5 million kilometers of Earth — about 20 times the distance to the Moon. Although none of them will strike the Earth in the next 100 years — not…
NASA的詹姆斯·韦伯太空望远镜发现了宇宙网最早的部分
天文学家利用NASA的詹姆斯·韦伯太空望远镜发现了一个由10个星系组成的丝状排列，这些星系在大爆炸后8.3亿年就存在了。
阿尔忒弥斯二号任务隔热罩安装完毕
Teams install the heat shield on the Artemis II Orion spacecraft at NASA’s Kennedy Space Center in Florida on June 22, 2023. The 16.5-foot-wide shield will ensure the safe return of the astronauts on board as the spacecraft travels at speeds of about 25,000 miles per hour and experiences outside temperatures of nearly 5,000 degrees Fahrenheit. See progress on Artemis II, the first crewed mission on NASA’s path to establishing a long-term presence at the Moon for science and exploration. Image Credit: NASA/Cory Huston 2023年6月22日，在NASA位于佛罗里达州的肯尼迪航天中心，团队正在为阿尔忒弥斯二号任务猎户座飞船安装隔热罩。当飞船以每小时2.5万英里的速度飞行，并经历近5,000华氏度的外部温度时，16.5英尺宽的隔热罩将确保宇航员安全返回。 查看阿尔忒弥斯二号任务的进展，这是NASA在月球上建立长期科学和探索的第一个载人任务。 影像来源：NASA/Cory Huston
来自引力宇宙的讯息
2023年6月29日 A Message from the Gravitational Universe Illustration Credit: NANOGrav Physics Frontier Center; Text: Natalia Lewandowska (SUNY Oswego) Explanation: Monitoring 68 pulsars with very large radio telescopes, the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has uncovered evidence for the gravitational wave (GW) background by carefully measuring slight shifts in the arrival times of pulses. These shifts are correlated between different pulsars in a way that indicates that they are caused by GWs. This GW background is likely due to hundreds of thousands or even millions of supermassive black hole binaries. Teams in Europe, Asia and Australia have also independently reported their results today. Previously, the LIGO and Virgo detectors have detected higher-frequency GWs from the merging of individual pairs of massive orbiting objects,…
迎接挑战：NASA TechRise学生团队开始飞行
Aerostar’s high-altitude balloon is shown here moments after launch carrying payloads from 20 student teams as part of NASA’s TechRise Student Challenge. Credits: Fresh Produce Students from 20 middle and high schools watched as their experiments launched aboard a high-altitude balloon on June 14 as part of NASA’s TechRise Student Challenge. The flight is part of a series of suborbital flight tests for TechRise that will continue through the summer. Led by NASA’s Flight Opportunities program and administered by Future Engineers, TechRise gives student teams a chance to design and build science and technology experiments for flight. “Flight test is a critical milestone along the path of technology development and scientific discovery, and is essential for tackling some of the most pressing challenges NASA faces.”…
M24：人马恒星云
2023年6月28日 Messier 24: Sagittarius Star Cloud Image Credit & Copyright: Emmanuel Astronomono Explanation: Unlike most entries in Charles Messier’s famous catalog of deep sky objects, M24 is not a bright galaxy, star cluster, or nebula. It’s a gap in nearby, obscuring interstellar dust clouds that allows a view of the distant stars in the Sagittarius spiral arm of our Milky Way galaxy. Direct your gaze through this gap with binoculars or small telescope and you are looking through a window over 300 light-years wide at stars some 10,000 light-years or more from Earth. Sometimes called the Small Sagittarius Star Cloud, M24’s luminous stars fill this gorgeous starscape. Covering over 3 degrees or the width of 6 full moons in the constellation Sagittarius, the telescopic field…
NASA的罗曼和ESA的欧几里得将联手研究暗能量
一台名为欧几里得的新太空望远镜将于7月发射，这是ESA在美国宇航局的资助下完成的一项任务，旨在探索宇宙膨胀加速的原因，即暗能量。到2027年5月，NASA的南希·格雷斯·罗曼太空望远镜将与欧几里得一起，以前所未有的方式探索这个谜题。
在肯尼迪航天中心晒太阳
A young alligator rests on a concrete structure at NASA’s Kennedy Space Center in Florida on April 25, 2023. Alligator breeding season starts in May when males begin courting females. By June, pairs have mated, and females build vegetation nests in the marsh. Eggs hatch in about 65 days. The mother carries her young to the water and protects them from predators, including male alligators. The center shares a border with the Merritt Island National Wildlife Refuge. More than 330 native and migratory bird species, 25 mammal, 117 fish, and 65 amphibian and reptile species call Kennedy and the wildlife refuge home. Learn more about alligators. Image credit: NASA/Ben Smegelsky 2023年4月25日，一只年轻的短吻鳄在佛罗里达州NASA肯尼迪航天中心的混凝土结构上休息。短吻鳄繁殖季节从五月开始，这时雄性开始向雌性求爱。到了6月，雌雄交配，雌性鳄鱼在沼泽里筑巢。鳄鱼卵大约65天后孵化。母鳄带着幼鳄来到水边，保护它们免受捕食者的伤害，包括雄性短吻鳄。 肯尼迪航天中心与梅里特岛国家野生动物保护区接壤。超过330种本地和候鸟，25种哺乳动物，117种鱼类，65种两栖动物和爬行动物将肯尼迪和野生动物保护区称为家。 了解更多关于短吻鳄的知识。 图片来源: NASA/Ben Smegelsky