Back in 1958, at the dawn of the space age, physicist James Van Allen discovered that the Earth is ringed by high-energy charged particles. Held in place by the planet's magnetic field, these bands of radiation were named the inner and outer Van Allen Belts. They're of particular interest to NASA as they pose a potential danger to spacecraft.

　　回到1958年，在和平岁月的曙光到来之际，物理学家詹姆斯?范?艾伦发现地球周围环绕着高能的带电粒子。这些辐射带依靠地球磁场来保持在太空中的位置，它们被命名为内外范艾伦辐射带。因为辐射带对飞船有潜在的危害，所以美航局对它特别关注。

　　Now a NASA mission also named for Van Allen has found something new about his belts. By looping through them repeatedly, the twin Van Allen Probes discovered a third band of radiation.

　　目前美航局的一项同样以范艾伦命名的计划又有了一个新发现。美航局发射的两个范艾伦探测器重复在空中作环状飞行时发现了第三个辐射带。

　　Or at least there were three. The two spacecraft uncovered the previously unknown structure in September. It consisted of fast-moving electrons, situated between the two previously known Van Allen Belts. The discovery was reported in the journal Science.

　　或者说至少还有第三个辐射带。9月份这两个飞行器发现了之前未知的结构。它由快速移动的电子组成，位于已为人们所熟知的两个范艾伦带之间。这一发现被《科学》杂志发表报道。

　　But the new structure is no longer. Four weeks after the probes found it, the third ring was wiped out by a strong shock wave emanating from the sun. Still, the unexpected finding shows that the Van Allen Belts are more complex and variable than had been assumed. And that seemingly well-established knowledge about space still may have the capacity to surprise.

　　但这个新结构已不复存在。在探测到这一结构四个星期之后，太阳发射的强烈冲击波将之化为幻影。不过这一意外的发现表明范艾伦带比之前想象的更复杂，更多变。人类对宇宙的探索在日趋完善，将来可能会有更多的惊喜。