On September 1st, 1859, miners following the Colorado gold rush woke up to another sunny day. Or so they thought. To their surprise, they soon discovered it was actually 1 am; and the sky wasn’t lit by the Sun, but rather by brilliant drapes of light. The blazing glow could be seen as far as the Caribbean, leading people in many regions to believe that nearby cities had caught fire. But the true cause of what would come to be known as the Carrington Event was a solar storm— the largest in recorded history.
1859 年 9 月 1 日, 追著科羅拉多淘金熱的礦工 醒來時又是個好天氣。 或至少他們以為如此。 沒多久,他們驚訝地發現 此時是凌晨一點; 天空並不是被太陽照亮的, 而是明亮的光幕。 遠從加勒比海都能看到這片強光, 導致許多地區的人都相信 鄰近的城市著火了。 這就是後來所知的卡靈頓事件, 而其背後的成因 是太陽風暴—— 有記錄以來最大的一次。
Solar storms are one of many astrophysical phenomena caused by magnetic fields. These fields are generated by movements of electrically charged particles like protons and electrons. For example, Earth’s magnetic field is generated by charged molten metals circulating in the planet's outer core. Similarly, the Sun’s magnetic field is generated by large convective movements in the plasma that composes the star. As this plasma slowly swirls, it creates areas of intense magnetic activity called sunspots. The magnetic fields that form near these regions often become twisted and strained. And when they’re stretched too far, they snap into simpler configurations, releasing energy that launches plasma from the Sun’s surface. These explosions are known as coronal mass ejections.
有許多天體物理現象都是由 磁場造成,太陽風暴也是其一。 這些磁場的成因, 是帶電荷的粒子移動, 比如光子和電子。 舉例來說, 地球的磁場的產生是因為熔化的金屬 在地球的外核中繞行。 太陽磁場產生的原因也很類似, 是組成星體的電漿中 大型的對流活動所造成。 當電漿緩慢地旋轉時, 會造成一些區域有劇烈的磁場活動, 稱為太陽黑子。 在這些區域附近形成的磁場 通常會扭曲變形。 當它們延展得太過頭時, 就會破裂開成為更簡單的結構, 釋放出能源,造成 電漿從太陽表面射出。 這些爆炸就是「日冕物質拋射」。
The plasma— mostly made of protons and electrons— accelerates rapidly,
電漿——大部分 由光子和電子組成——
quickly reaching thousands of kilometers per second. A typical coronal mass ejection covers the distance between the Sun and the Earth in just a couple of days, flowing along the magnetic field that permeates the solar system. And those that cross the Earth’s path are drawn to its magnetic field lines, falling into the atmosphere around the planet’s magnetic poles. This tidal wave of high-energy particles excites atmospheric atoms such as oxygen and nitrogen, causing them to rapidly shed photons at various energy levels. The result is a magnificent light show we know as the auroras. And while this phenomenon is usually only visible near the Earth’s poles, strong solar storms can bring in enough high energy particles to light up large stretches of the sky.
會快速加速。 很快就達到每秒鐘數千公里。 典型的日冕物質拋射 只要花幾天的時間 就能達到地球, 它會沿著散布在太陽系 各處的磁場流動。 而經過地球路徑的拋射 則會被其磁場線給拉過去, 在地球的磁極附近落入大氣當中。 這些高能粒子潮波 會激發大氣中的原子,如氧及氮, 造成它們在各能階 快速放射出光子。 結果就是壯麗的亮光秀, 即我們所知道的極光。 雖然這種現象通常只有 在地球極地附近才能看見, 但強力的太陽風暴 會帶來足夠的高能粒子, 點亮大片的天空。
The magnetic fields in our solar system are nothing compared to those found in deep space. Some neutron stars generate fields 100 billion times stronger than those found in sunspots. And the magnetic fields around supermassive black holes expel jets of gas that extend for thousands of light years. However, on Earth, even weak solar storms can be surprisingly dangerous. While the storms that reach us are generally harmless to humans, the high-energy particles falling into the atmosphere create secondary magnetic fields, which in turn generate rogue currents that short-circuit electrical equipment. During the Carrington Event, the only widespread electrical technology was the telegraph. But since then, we've only become more dependent on electrical systems. In 1921, another powerful solar storm caused telephones and telegraph equipment around the globe to combust. In New York, the entire railway system was shut down and fires broke out in the central control building. Comparatively weak storms in 1989 and 2003 turned off regions of the Canadian power grid and damaged multiple satellites. If we were hit by a storm as strong as the Carrington Event today, it could devastate our interconnected, electrified planet.
我們太陽系中的磁場 和深太空的磁場相比, 可說是小巫見大巫。 有些中子星所產生的磁場, 是太陽黑點磁場的一千億倍。 且,在超大質量黑洞附近的磁場 產生的噴流可以達數千光年之遠。 然而,在地球上, 即使是很弱的太陽風暴 也有驚人的危險性。 雖然到達地球的風暴一般對人無害, 落入大氣當中的高能粒子 會造成次生磁場, 次生磁場則會產生猛烈的電流, 讓電子設備短路。 在卡靈頓事件發生時, 唯一普及的電子技術就是電報。 但在那之後,我們更加依賴電子系統。 1921 年, 另一場強大的太陽風暴造成 全球各地的電話和電報設備燒壞。 在紐約,整個鐵路系統都停擺, 中央控制大樓還發生火災。 1989 年及 2003 年的 風暴相對比較弱, 造成加拿大電力網的許多區域停電, 也損壞了數個衛星。 如果現今我們面臨 卡靈頓事件時那麼強的風暴, 我們這個相互連結的電氣化 星球可能會受到重挫。
Fortunately, we're not defenseless. After centuries of observing sunspots, researchers have learned the Sun’s usual magnetic activity follows an 11-year cycle, giving us a window into when solar storms are most likely to occur. And as our ability to forecast space weather has improved, so have our mitigation measures. Power grids can be shut off in advance of a solar storm, while capacitors can be installed to absorb the sudden influx of energy. Many modern satellites and spacecraft are equipped with special shielding to absorb the impact of a solar storm. But even with these safeguards, it’s hard to say how our technology will fare during the next major event. It’s possible we’ll be left with only the aurora overhead to light the path forward.
幸運的是,我們並非毫無防備。 在觀察了太陽黑子數百年之後, 研究者發現,太陽的磁場活動通常 是十一年一個循環, 讓我們能知道太陽風暴 可能發生的時間。 且,隨著我們預測 太空天氣的能力更進步, 我們用來緩和風暴的措施也進步了, 可以在太陽風暴來襲之前 先把電力網關閉, 也可以安裝電容器, 來吸收突然流入的能量。 許多現代的衛星及太空船 也都裝備有特殊的屏障, 可以吸收太陽風暴的衝擊。 但,即使有這些保護, 還是很難說在下次重大事件時 我們的科技是怎樣的狀況。 有可能,我們會只剩下頭上的極光 來照亮向前的路。