Struck by a cosmic ray: Galactic particles may have forced a passenger jet to make an emergency landing

宇宙射线击中客机：银河粒子或是紧急迫降因素

A stream of high-energy particles from a distant supernova explosion may have caused a packed passenger jet to suddenly lose altitude in late October, forcing an emergency landing.

10月下旬，远距离超新星爆炸产生了一束高能粒子流，这有概率导致一架满载的客机突然从高空下降，致使紧急迫降。

The incident took place on Oct. 30 and involved a JetBlue Airbus A320 aircraft heading from Cancun, Mexico, to Newark in New Jersey. According to available reports, the aircraft suddenly dropped down in the air without an obvious reason while cruising above Florida. Although the pilots quickly regained control of the plane, at least 15 passengers were injured in the incident, forcing the pilots to make an emergency landing at Tampa International Airport. Earlier this week, Airbus issued a statement attributing the incident to "intense solar radiation" which may have corrupted "data critical to the functioning of flight controls." The manufacturer subsequently grounded 6,000 A320s to roll out software updates to fix the vulnerability.

该事件发生在10月30日，涉及一架从墨西哥坎昆飞往新泽西州纽瓦克的捷蓝航空空客A320飞机。根据现有报道，这架飞机在佛罗里达州上空巡航时突然从空中坠落，且无任何明显原因。尽管飞行员很快夺回了飞机的控制权，但仍有至少15名乘客因事故受伤，导致飞行员紧急迫降于坦帕国际机场。本周早些时候，空客公司发表声明，将这一事件归因于“强烈的太阳辐射”，有可能因此破坏了“对飞行控制功能至关重要的数据”。制造商随后停飞了6000架A320，并推出更新后的软件进行查漏补缺。

But there is a catch: Solar radiation levels on Oct. 30 were unremarkable and nowhere near levels that could affect aircraft electronics, Clive Dyer, a space weather and radiation expert at University of Surrey in the U.K., told Space.com. Instead, Dyer, who has studied effects of solar radiation on aircraft electronics for decades, thinks the onboard computer of the affected jet could have been struck by a cosmic ray, a stream of high-energy particles from a distant star explosion that may have travelled millions of years before reaching Earth.

但有一点值得注意：英国萨里大学大气辐射专家克莱夫·戴尔(Clive Dyer)在Space.com说到，10月30日当天的太阳辐射并不明显，远未达到影响飞机电子设备的水平。相反，戴尔根据几十年来对太阳辐射影响飞机电子设备的研究，认为喷气式飞机的机载计算机可能被宇宙射线击中。宇宙射线是来自遥远恒星爆炸的高能粒子流，到达地球之前可能传播了有数百万年。

"[Cosmic rays] can interact with modern microelectronics and change the state of a circuit," Dyer said. "They can cause a simple bit flip, like a 0 to 1 or 1 to 0. They can mess up information and make things go wrong. But they can cause hardware failures too, when they induce a current in an electronic device and burn it out."

戴尔说：“宇宙射线能与现代微电子设备相互影响，并改变电路的状态，由此导致一个简单的位翻转，比如由0变1或由1变0。它们可以打乱信息，导致出错。但当它们在电子设备中感应出电流并烧坏电流时，它们也会导致硬件故障。”

Cosmic rays frequently arise when massive stars explode in supernovas at the end of their lives. The explosions accelerate streams of protons, hurling them across the universe at the speed of light. Cosmic rays batter Earth's atmosphere constantly, interacting with molecules of air and producing showers of exotic particles such as muons, high energy neutrons and positrons. As these particles rain down on Earth, they may hit an electronic circuit inside an aircraft sensor or onboard computer causing what researchers call a single-event upset.

宇宙射线经常产生于大质量恒星生命结束时的超新星爆炸，爆炸加速了质子流的传播，以光速将其射向宇宙。宇宙射线不断冲击着地球大气层，与空气中的粒子相互作用，产生奇特粒子，如μ子、高能中子和正电子。当这些粒子如雨点般落在地球上时，它们可能会冲击飞机传感器或机载计算机内部的电子电路，导致研究人员所描述的单事件扰动。

Bursts of energy from the sun in the form of solar flares are also a source of such particles and can be dozens of times more energetic, or in extreme cases thousands of times, and therefore more damaging than particles from cosmic ray showers. When the sun gets active, incidents caused by single-event upsets in aircraft electronics may become more common.

太阳耀斑的能量爆发也是粒子的来源，其爆发的能量可能比宇宙射线的粒子高几十倍，在极端情况下会高几千倍，因此更具破坏性。在太阳活动的剧烈期，由单事件扰动引起的飞机电子设备故障会变得更加常见。·

In fact, less than two weeks after the JetBlue incident, potentially dangerous levels of solar radiation caused by a powerful solar flare persisted in the atmosphere at flight altitudes for several days. The Airbus software update therefore makes sense, even though, according to Dyer, solar activity couldn't have been responsible for the BlueJet accident.

事实上，在捷蓝航空事件发生后不到两周，强大的太阳耀斑引起了太阳辐射，其停留在飞行高度的大气层有一定天数，具有潜在威胁。因此，尽管戴尔表示太阳活动不可能是捷蓝航空事件的原因，空客的软件更新是有意义的。

"It's down to manufacturers to produce hardy electronics, especially in safety critical units," Dyer said. "A slight problem is that over 20 years, they've become complacent, because there have not been any [significant solar weather] events."

戴尔说：“制造商有责任生产不易破坏的电子产品，尤其是有关安全的关键设备。但这里有一个小问题，20多年来，因为没有经历过任何有关‘重大太阳活动事件’，他们已经变得松懈了。”

For Dyer, the effects of cosmic radiation on spacecraft and aircraft electronics are a life-long professional interest. In the 1980s, he was a part of a team that researched single-event upsets in spacecraft and later flew radiation monitors on the Concorde. He believes that single-event upsets in aircraft electronics due to cosmic rays, although rare, are not unprecedented.

对于戴尔来说，研究宇宙辐射对航天器和飞机电子设备的影响，是他一生的专业兴趣。20世纪80年代，他是研究航天器单事件扰动团队中的一员，此后操控了协和式飞机上的辐射监测仪。他认为，宇宙射线对飞机电子设备造成的单事件扰动虽然罕见，但并非史无前例。

In fact, Dyer thinks that a 2008 incident of the Quantas Flight 72 was likely produced by such a particle strike. Back then, the affected aircraft, an Airbus 330, nosedived twice on its own while cruising above the Pacific Ocean, creating brief spells of near weightlessness. Unfortunately, the passengers weren't prepared to be suddenly thrown in the air and many sustained serious injuries.

事实上，戴尔认为，2008年澳洲航空72号班机的事故，很有可能是因为这种粒子的冲击。当时这一架空客330受到了影响，在太平洋上空巡航时自动俯冲两次，造成短暂的失重状态。不幸的是，乘客们毫无准备就突然被抛向半空，导致多人重伤。

Dyer, who served as an advisor in the investigation at that time, said that although the incident was traced back to faults in the aircraft's electronic sensors, the investigation concluded without finding a definitive cause.

当时在调查中担任顾问的戴尔表示，尽管事件起因可以定位到飞机电子传感器的故障，但调查却在没有确切原因的情况下草草结束。

"They never got to the fundamental cause of the bit flip in the device," Dyer said. "It was left open, surprisingly."

戴尔说：“他们从未找到设备出现位翻转的根本原因，更令人惊讶的是，设备一直在运转。”

With the sun being rather active lately, the chances of serious incidents caused by energetic solar flares are on the rise.

由于最近太阳活动相当活跃，高能太阳耀斑引起严重事故的几率正在上升。

"You can get huge increases [in particle radiation] from the sun," said Dyer. "A thousand times higher than cosmic rays, and then many aircraft could be bothered by it."

戴尔说：“你可以从太阳那里获得大量的[粒子辐射]，这比宇宙射线的辐射高一千倍，因此很多飞行器都可能受到它的困扰。”

The Airbus software update has certainly been needed, even though the JetBlue incident was unlikely caused by solar weather. Airbus has yet to respond to Space.com's request for comment at time of publication.

空客的软件更新当然是必要的，尽管捷蓝航空事件不太可能是由太阳活动引起的。截至发稿时，空客公司尚未回应Space.com的置评请求。