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    Various companies are pressing ahead with plans for internet service from space, which has prompted astronomers to voice concerns about the impact on research from telescopes on Earth.


    On Monday morning, SpaceX launched one of its reusable rockets from Cape Canaveral, Fla., carrying 60 satellites into space at once. It was the second payload of Starlink, its planned constellation of tens of thousands of orbiting transmitters to beam internet service across the globe.


    Successful deployment of 60 Starlink satellites confirmed! pic.twitter.com/bpBqO9oYR3

    确认成功部署了60颗Starlink卫星! pic.twitter.com/bpBqO9oYR3

    - SpaceX (@SpaceX) November 11, 2019

    - SpaceX(@SpaceX)2019年11月11日

    When SpaceX, the private rocket company founded by Elon Musk, launched the first batch of Starlink orbiters in May, many astronomers were surprised to see that the satellites were extremely bright, causing them to fear that the constellation would wreak havoc on scientific research and transform our view of the stars. Since then, many scientists have been on a mission to better quantify the impacts of Starlink and to share their concerns with SpaceX.

    当埃隆·马斯克(Elon Musk)创立的私人火箭公司SpaceX在5月发射了第一批Starlink轨道器时,许多天文学家惊讶地发现这些卫星非常明亮,这使他们担心该星座会严重破坏科学研究和改造。我们对星星的看法。自那时以来,许多科学家一直在执行任务,以更好地量化Starlink的影响并与SpaceX分享他们的担忧。

    In response, SpaceX has said that it wants to mitigate the potential impacts of Starlink. But at the same time, the company is still moving full steam ahead.


    Whoa, it worked!!


    - Elon Musk (@elonmusk) October 22, 2019

    -Elon Musk(@elonmusk)2019年10月22日

    In October, Mr. Musk announced that he was using Twitter via a Starlink internet connection, as his company was requesting permission from the Federal Communications Commission to operate as many as 30,000 satellites on top of the 12,000 already approved. Should SpaceX succeed in sending this many satellites to low-Earth orbit, its constellation would contain more than eight times as many satellites as the total number currently in orbit.


    That move added to the worries of many astronomers.


    When James Lowenthal, an astronomer at Smith College, first saw the train of Starlink satellites marching like false stars across the night sky in the spring, he knew something had shifted.

    当史密斯学院的天文学家詹姆士·洛文塔尔(James Lowenthal)首次看到春季时,星链卫星像假星一样在夜空中行进时,他知道情况已经发生了变化。

    “I felt as if life as an astronomer and a lover of the night sky would never be the same,” he said.


    Most of the first Starlink nodes have since moved to higher orbits and are now invisible for most of us who live under bright city lights. But they are still noticeable from places with dark skies. If thousands more of these satellites are launched, Dr. Lowenthal said he feared “it will look as if the whole sky is crawling with stars.”


    Since May, the American Astronomical Society has convened an ad hoc committee with Dr. Lowenthal and other experts to discuss their concerns with SpaceX representatives once a month.


    At the same time, SpaceX has been working directly with the National Radio Astronomy Observatory, a federally funded research center that operates facilities across the world, to jointly minimize potential impacts of Starlink satellites on radio wavelengths that astronomers use.


    But these conversations did not focus on light pollution, a problem presented by the reflective surfaces of proposed satellite constellations such as Starlink. At first, SpaceX said the complication would be minimal, and the new committee is trying to assess the impact and actively find solutions.


    “So far, they’ve been quite open and generous with their data,” Dr. Lowenthal said. “But they have not made any promises.”

    Lowenthal博士说:“到目前为止,他们对数据非常开放和慷慨。” “但是他们没有做出任何承诺。”

    A spokeswoman from SpaceX said the company was taking steps to paint the Earth-facing bases of the satellites black to reduce their reflectiveness. But Anthony Tyson, an astronomer at the University of California, Davis, said that wouldn’t solve the problem.


    Dr. Tyson is the chief scientist for the Large Synoptic Survey Telescope - a 27-foot, billion-dollar telescope under construction in Chile that will scan the entire sky every three days. The survey, the world’s largest yet, will help astronomers better understand dark energy, dark matter, the origin of the Milky Way and the outer regions of the solar system. But because it is designed to scan faint objects, it is expected to be greatly affected by the satellites.


    Dr. Tyson’s simulations showed that the telescope would pick up Starlink-like objects even if they were darkened. And they wouldn’t just affect a single pixel in a photograph. When there is a single bright object in the image, it can create fainter artifacts as well because of internal reflections within the telescope’s detector. Moreover, whenever a satellite photobombs a long-exposure image, it causes a bright streak of light that can cross directly in front of an object astronomers wish to observe.


    “It’s really a mess,” Dr. Tyson said.


    Knowing how challenging it would be to correct these interrupted images, Dr. Tyson decided the best step forward was to set the telescope to avoid Starlink satellites. While simulations based on the earlier 12,000-satellite total suggested that would be possible, SpaceX’s application for 30,000 additional satellites upset the calculations.


    “We’re redoing the models now just to see what’s visible at any one time - and it’s really quite frightening,” said Patrick Seitzer, a professor of astronomy emeritus at the University of Michigan, who has been running similar analyses to determine how many satellites will be visible and when.

    密歇根大学天文学名誉教授帕特里克·塞泽特(Patrick Seitzer)说:“我们现在正在重做模型,以便随时查看可见的事物,而且确实令人恐惧。”他一直在进行类似的分析以确定多少卫星将在何时可见。

    His preliminary results suggest that avoiding the satellites would be difficult during twilight - a serious problem given that potentially hazardous asteroids and many objects in the solar system are best seen during this time. The satellites thus limit the ability of astronomers to observe them.


    And Dr. Tyson’s early simulations also confirm the potential problems, demonstrating that over the course of a full year, the giant telescope wouldn’t be able to dodge these satellites 20 percent of the time. Instead, those images would be effectively ruined.


    Team is go for launch of 60 Starlink sats tomorrow-heaviest payload to date, first re-flight of a fairing, and first Falcon 9 to fly a fourth mission. Watching 1 sat that may not orbit raise; if not, 100% of its components will quickly burn up in Earth’s atmosphere pic.twitter.com/OrI8L0ntFK


    - SpaceX (@SpaceX) November 11, 2019

    - SpaceX(@SpaceX)2019年11月11日

    SpaceX’s 30,000 satellites might also just be the start as other companies, such as Amazon, Telesat and OneWeb, plan to launch similar mega-constellations.


    “If there are lots and lots of bright moving objects in the sky, it tremendously complicates our job,” Dr. Lowenthal said. “It potentially threatens the science of astronomy itself.”

    洛文塔尔博士说:“如果天空中有很多明亮的运动物体,那将极大地使我们的工作复杂化。” “它潜在地威胁着天文学本身。”

    Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics who closely tracks objects in orbit, agrees.

    哈佛-史密森天体物理学中心的天文学家乔纳森·麦克道威尔(Jonathan McDowell)对此表示赞同。

    “There is a point at which it makes ground-based astronomy impossible to do,” he said. “I’m not saying Starlink is that point. But if you just don’t worry about it and go another 10 years with more and more mega-constellations, eventually you are going to come to a point where you can’t do astronomy anymore. And so let’s talk about it now.”

    他说:“在某种程度上,它使地面天文学无法完成。” “我并不是说Starlink就是这一点。但是,如果您只是不担心它,并且又用越来越多的巨型星座再走了10年,那么最终您将到达无法再进行天文学的地步。因此,让我们现在谈论它。”

    While astronomers are starting those conversations, they have little legal recourse. There are no regulations in place to protect the skies against light pollution.


    “International space law is pretty wide open,” said Megan Donahue, an astronomer at Michigan State University and the president of the American Astronomical Society. While many astronomers have been concerned about radio interference and space debris, she says light pollution is a bigger concern because there are no rules in place. That means any path forward relies on the good will of SpaceX and other companies.

    密歇根州立大学的天文学家,美国天文学会会长梅根·多纳休(Megan Donahue)说:“国际空间法是相当开放的。”她说,尽管许多天文学家一直在关注无线电干扰和太空碎片,但由于没有相关规定,光污染是一个更大的问题。这意味着任何前进的道路都取决于SpaceX和其他公司的良好意愿。

    “It’s more of a philosophical question,” Dr. Donahue said. “It kind of boils down to: How much do I trust corporate good will, and how much would a corporation care about the opinion of people who care about science and astronomy?”

    多纳休博士说:“这更多是一个哲学问题。” “归结为:我对公司的善意有多大的信任?公司对关心科学和天文学的人们的意见有多大兴趣?”



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