Mysterious blue spiral spotted over European skies. What was it? (photos)
欧洲上空出现的神秘蓝色漩涡，到底是什么？（照片）
Is it a plane? Is it a satellite? Is it a galaxy? Is it aliens? A strange blue spiral lit up the skies over Europe on Monday night (March 24), causing residents of the U.K. and other European countries like Croatia, Poland, and Hungary to flood social media with photos and videos, along with requests to identify this weird light. Some users even speculated that the spiral could be the work of aliens!
是飞机吗？还是卫星吗？难道是星系吗？总不会是外星人吧？周一晚上（3月24日），一个神秘的蓝色漩涡照亮欧洲上空，一时间，英国，克罗地亚、波兰以及匈牙利等欧洲国家的居民，竞相在社交媒体上发布照片和视频，要求查明这种的光是怎么形成的。甚至有网民猜测，这可能是外星人搞出的动静！
Space.com can reveal the identity of the object behind this spectacular event, and unfortunately (possibly reassuringly), rather than being the work of extraterrestrial visitors, it's a bit more down to Earth.
航天机构揭开了此番壮观景象的神秘面纱，遗憾的是（或许是为了安定人心），它表示这并不是地外生命的杰作，而是人为的结果。
The cause of the strange blue spiral is actually a SpaceX Falcon 9 rocket that blasted off from Space Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station in Florida at 1:48 p.m. EDT (1748 GMT) on Monday. The rocket was carrying the secretive NROL-69 mission for the National Reconnaissance Office (NRO).
造成神秘蓝色漩涡的罪魁祸首实际是SpaceX猎鹰9号火箭，该火箭于美国东部时间周一下午1点48分（格林威治时间1748）从佛罗里达州卡纳维拉尔角太空部队站的40号航天发射中心（SLC-40）发射升空，为侦察办公室(NRO)用于执行NROL-69的秘密任务。
The spiral appeared over Europe at around 4 pm EDT (2000 GMT) and persisted in the sky for a few minutes. The X feed of Shanghai Daily shared a stunning timelapse video of the spiral appearing and expanding over the skies of Croatia.
美国东部时间下午4点左右（格林威治时间2000），欧洲上空出现了蓝色漩涡并持续了好几分钟。《上海日报》的X feed发布了一段延时视频，视频中克罗地亚上空出现蓝色漩涡并不断扩大，令人叹为观止。
As the above post indicates, the strange blue whirlpool, which to many social media users resembled a spiral galaxy, is an example of what some people call a "SpaceX spiral." These structures develop after the upper stage of a Falcon 9 rocket has separated from its first-stage booster.
正如上文所述，于许多社交媒体用户而言，充满神秘的蓝色漩涡像极了螺旋星系，人们所说的“SpaceX螺旋”就是其中一个例子。这些漩涡状的结构是在猎鹰9号火箭的上身与其第一级助推器分离后形成的。
As the upper stage continues towards space, the lower stage falls back to Earth. As this happens, the booster stage begins to spiral, simultaneously dumping what remains of its fuel. Due to the altitude at which this fuel is ditched, it freezes instantly, preserving a swirling pattern created by the booster's motion.
火箭上身向太空不断前进时，下身则落回地球。当这种情况发生时，增压级开始螺旋上升，同时会丢弃剩余的燃料。由于当时燃料处于高空，一经丢弃立刻就会冻结，助推器前进所产生的螺旋形状则会保留下来。
When light reflects from this structure, it creates these strange-looking manifestations in the sky.
当光线经螺旋结构反射后，就会在天空中产生这些奇怪的景象。
X user Merlin Tomkins captured the wonder and mystery of this object in images posted to his X feed.
X用户梅林·汤姆金斯用摄影机捕捉到这一神奇景象并将其发布在X feed上
X user Shu from Wolverhampton in England was slightly more concerned about the spiral manifestation in the sky, writing on his X feed: "So it seems many of us across Europe (I am in Wolves UK) just witnessed an object in the sky, I thought it was the moon behind cloud at first until it started moving with spiraling light emanating from it... any ideas?"
来自英国伍尔弗汉普顿的X用户Shu则更关心空中的螺旋运动，他在X feed上写道：“很多欧洲人（当时我在英国狼队）刚才都看到天上有一个东西，一开始我以为是月亮被云朵遮挡住了，然而它却开始移动，并发出漩涡般的光芒……大家怎么认为呢？”
Physicist and science communicator Brian Cox took to his X feed to reassure U.K. and European citizens like Merlin and Shu that the event they witnessed was associated with the SpaceX launch earlier that day.
布赖恩·考克斯(Brian Cox)是一名物理学家及科学传播者，他在X feed上向梅林和舒等英国及欧洲公民保证，他们所看到的景象与当日早些时间的SpaceX发射确有关系。
Though the spiral has a terrestrial origin, that doesn't mean its manifestation in the sky is any less spectacular in appearance.
虽然漩涡一开始出现在地球，但这并不意味着它空中看上去就没有那么壮观。
Daniel Puchalski posted images of the blue spiral in the Facebook group Smartphone Astrophotography, commenting: "Captured this stunning sight of a Falcon 9 fuel dump over Poland! Taken handheld with a Xiaomi 14 Ultra. An unforgettable view!"
Daniel Puchalski在Facebook群组Smartphone Astrophotography中发布了蓝色螺旋的图像，并说道：“用小米14UItra拍摄到了猎鹰9号在波兰上空倾倒燃料的惊人景象！真是令人难忘！”
He also shared the incredible photos with Space.com.
他还将这些令人惊叹的照片发布在Space.com上。
Astronomer Allan Trow caught the spiral with an icy white hue over the sky of Bannau Brycheiniog National Park in Wales. He shared the image via his @AlDarkSkyWales X account.
天文学家艾伦·特罗在威尔士Bannau Brycheiniog国家公园的天空中拍摄到了冰白色的漩涡。并通过自己的@AlDarkSkyWales X账户分享了这张照片。
X user matts shared an incredible video of the SpaceX spiral gradually fading from the sky over the course of around 3 minutes.
X用户matts则发布了SpaceX螺旋从天空中逐渐消失的景象，历时三分钟，令人拍案叫绝。
SpaceX spirals like this one seen over the U.K. and Europe remain fairly rare, but with Falcon 9 and other rocket launches becoming more common, they are likely to soon become a more familiar sight.
如同今日这般在英国和欧洲上空所看到的SpaceX螺旋仍然相当罕见，但随着猎鹰9号和其他火箭发射越来越常见，这一景象也将愈为人所熟知
Some people may be disappointed by the rational explanation for this spiral light in the night sky. The aforementioned Shu responded to a commentator discussing the spiral's true identity: "I wish it was an invasion; I could use the time off work."
以这样一种理由来解释夜空中出现的螺旋光，有些人或许会感到感到失望。舒在回应一位议论漩涡真实来源的评论员时说到：“我到希望这是一次入侵；这样我刚好就可以早点下班了。”
We feel you Shu!
舒，我们与你感同身受!
