美國航天局探祕範艾倫輻射帶

One of the first discoveries of the space age, made in 1958, was that the Earth is surrounded with a doughnut-shaped field of highly charged particles. It was named the Van Allen radiation belt, after its discoverer, U.S. space scientist James Van Allen.

人類進入太空時代以來的首批探索成果之一，即是1958年對於地球周圍高能電磁場的發現。該磁場隨後被命名爲範艾倫輻射帶，以紀念其發現者、美國空間科學家詹姆斯·範·艾倫。

But not much was known about it until NASA launched two probes in 2012. Scientists say the data they sent back to earth is very exciting.

然而，在2012年美國航空航天局發射兩顆專門探測器之前，人類對於此區域還知之甚少。科學家稱，由探測器傳回地面的數據，足以令人振奮。

Space weather can be as unpredictable as the weather on earth. Periodic eruptions on the sun's surface eject huge clouds of highly charged protons and electrons.

宇宙氣象與地面氣象一樣難以預測。太陽表面的週期性爆發，釋放出大規模、高電荷的質子與電子。

Some of them reach the earth and cause spectacular light displays like the Aurora Borealis or Northern Lights.

其中有一些可以傳送到地球，引起像北極光這樣光影奇觀。

When the clouds of charged particles are unusually strong, they can knock out power grids, disrupt communications and even damage electronic equipment.

當這些帶電粒子異常強大之時，他們會影響電網、中斷通信、甚至損壞電子設備。

But most of the time they get trapped by the earth’s magnetic field in the so-called the Van Allen radiation belt.

但大多數情況下，它們都會被地球自身的磁場所阻攔，而後者被人們稱之爲範艾倫輻射帶。

Nevertheless, they can still inflict damage, says NASA’s program scientist, Mona Kessel.

不過，美國航空航天局的項目科學家莫娜·凱塞爾說，仍然會有一些破壞。

"We also have a lot of satellites that fly through that area - communications satellites, navigation satellites - and so we need to understand what it is that the effects are, because the effects can be quite dramatic, " said Kessel.

凱塞爾說：“我們有許多衛星飛過那個區域，通訊衛星、導航衛星等。因此我們必須弄清楚影響是什麼，因爲這些影響可能會很大。”

To learn more about space weather, NASA in 2012 launched a pair of satellites built by Applied Physics Laboratory. Called Van Allen Probes, they were to explore the mysterious belt. At first researchers expected only quantitative data, says project scientist Barry Mauk.

爲了更好地瞭解宇宙氣象，美國航空航天局於2012年發射了一對名爲範艾倫號的探測器。探測器由應用科學實驗室所研製，用以探索這片神祕區域。參與此項目的科學家巴里·莫克說，一開始他們只想得到一些定量數據。

“I was skeptical we would find anything surprising. In fact, we found tremendous surprise. We found new structures that we never anticipated, " said Mauk.

應用物理實驗室項目科學家巴里·莫克說： “剛開始我對於我們是否能夠有特殊發現持懷疑態度。實際上，我們後來有許多驚人的發現。我們發現了我們預料之外的結構形態。”

The Van Allen Probes discovered that, instead of two layers, the belt has an occasional third layer of charged particles and that they sometimes form zones called ‘zebra stripes’. The probes also found how the electric and magnetic fields additionally energize the particles.

範艾倫輻號探測器發現，除去已知的兩層結構，該地帶還偶有第三層帶電粒子存在。而它們有時會形成所謂“斑馬條紋”的區域。探測器還發現了電場和磁場是如何作用於這些粒子的。

Mauk says measurements gathered by the two probes will help scientists develop computer models for creating space weather forecasts.

莫克說兩個探索器所收集的數據會幫助科學家開發出電腦模型，以預測宇宙氣象的變化。

“If I see something at the sun, some flare or something, and I can measure the magnetic field on the sun - there are remote ways of doing that - I can now predict how will the radiation belts respond to that, " he said.

莫克說： “如果我觀察到太陽的活動，比如表面爆發，我就可以測量太陽上的磁場，這是遠距離的測量方法。現在我可以預測輻射帶對於太陽活動的反應。”

And that, he says, may lead to sending the astronauts to their vaults or powering down the communication and navigation satellites while this effect passes by.

他說，在此基礎上，在這些影響來臨之時，可以讓宇航員返回座艙，或者是中斷通信和導航衛星等。

"And then we also just want to understand it because it's a very dynamic part of our whole space, above the earth, our electromagnetic space, " said Kessel.

NASA項目科學家莫娜·凱塞爾說：“我們想了解這些是因爲這是整個宇宙空間十分活躍的一部分，即在地球之上的，我們的電磁場空間。”

Scientists say better understanding of the Van Allen radiation belt will help us prepare for potential surprises from our own sun.

科學家稱，對於範艾倫輻射帶的更好了解有助於我們做好準備，預防太陽活動帶來的潛在影響。