每日一图

On June 26, 2020, NASA astronauts Bob Behnken and Chris Cassidy conducted the first of two spacewalks to swap batteries and upgrade power systems on the International Space Station’s Starboard-6 truss structure. Behnken is pictured here during the six-hour and seven-minute excursion. The two astronauts conducted a second spacewalk on July 1 to complete the upgrades. Image Credit: NASA 2020年6月26日，美国宇航局(NASA)宇航员鲍勃·本肯(Bob Behnken)和克里斯·卡西迪(Chris Cassidy)进行了两次太空行走中的第一次，以交换电池并升级了国际空间站右板-6桁架结构上的电源系统。本肯在6小时7分钟的游览中被拍到。这两名宇航员在7月1日进行了第二次太空行走，以完成升级。 影像来源：NASA

June 30 is Asteroid Day. Asteroids, sometimes called minor planets, are rocky, airless remnants left over from the early formation of our solar system about 4.6 billion years ago. The current known asteroid count is 958,967. This image was taken using the 200-inch Hale telescope on Palomar Mountain by astronomers at the Jet Propulsion Laboratory of the Deep Space 1 spacecraft at a distance of 2.3 million miles (3.7 million kilometers) from Earth. Tracing a path against the constellation Gemini. This image was obtained on Nov. 16, 1998, 23 days after the spacecraft’s launch from Cape Canaveral, FL. The spacecraft was receding from Earth at a speed of 1.1 miles per second relative to Earth. The spacecraft, just 4.9 feet high, was 4 million times…

The galaxy known as NGC 5907 stretches wide across this image. Appearing as an elongated line of stars and dark dust, the galaxy is categorized as a spiral galaxy just like our own Milky Way. In this new image from the NASA/ESA Hubble Space Telescope, we don’t see the beautiful spiral arms because we are viewing it edge-on, like looking at the rim of a plate. It is for this reason that NGC 5907 is also known as the Knife Edge galaxy. The Knife Edge galaxy is about 50 million light-years from Earth, lying in the northern constellation of Draco. Although not visible in this image, ghostly streams of stars on large arching loops extend into space, circling around the galaxy; they are believed to…

As nuclear fusion engines, most stars live placid lives for hundreds of millions to billions of years. But near the end of their lives they can turn into crazy whirligigs, puffing off shells and jets of hot gas. In this image NGC 7027 resembles a jewel bug, an insect with a brilliantly colorful metallic shell. Recently, NGC 7027’s central star was identified in a new wavelength of light — near-ultraviolet — for the first time by using Hubble’s unique capabilities. The near-ultraviolet observations will help reveal how much dust obscures the star and how hot the star really is. This object is a visibly diffuse region of gas and dust that may be the result of ejections by closely orbiting binary stars that were first…

NASA astronauts (from top) Chris Cassidy and Robert Behnken work on U.S. spacesuits inside the International Space Station’s Quest airlock. The two are slated to conduct spacewalks on Friday, June 26, and Wednesday, July 1, to begin the replacement of batteries for one of the power channels on the orbiting laboratory. The spacewalking astronauts will replace aging nickel-hydrogen batteries for one of two power channels on the far starboard truss (S6 Truss) of the station with new lithium-ion batteries that arrived to the station on a Japanese cargo ship last month. The battery replacement work is the culmination of power upgrade spacewalks that began in January 2017. Image Credit: NASA 美国国家航空航天局的宇航员（顶部）克里斯·卡西迪（Chris Cassidy）和罗伯特·贝肯（Robert Behnken）在国际空间站的探索气舱内研究美国宇航服。他们两人将于6月26日(周五)和7月1日(周三)进行太空行走，以开始为轨道实验室中的一个电源通道更换电池。 太空行走的宇航员将用新的锂离子电池替换空间站远右板桁架(S6桁架)上两个动力通道中的一个老化的镍氢电池，这些电池是上个月由一艘日本货船运至空间站的。更换电池的工作是2017年1月开始的太空行走中能源升级的高潮。 影像来源：NASA

Pilots Troy Asher and Stu Broce walk out of NASA’s Armstrong Flight Research Center’s (AFRC) hangar in Palmdale, California, toward the flight line. In addition to aeronautics research, Flight Operations personnel support such missions as the Mars Perseverance Rover, slated to launch in July 2020. Armstrong’s Building 703 in Palmdale opened in 2007 at the former Rockwell International/North American Aircraft production facility in Palmdale. The Los Angeles World Airports Board of Airport Commissioners endorsed a 20-year lease agreement with NASA for use of a large hangar and surrounding acreage at the facility adjacent to U.S. Air Force Plant 42. Specialized science platform aircraft, such as the DC-8 flying laboratory, high-altitude research aircraft ER-2s, C-20A, Gulfstream III and the Stratospheric Observatory for Infrared Astronomy, are based…