想看極光　把握最後機會

看極光是你一直以來的夢想嗎？科學家預測在2023年以前，2016年是容易看到極光的最後一年， 因此在你錯失機會前最好趕快！

撰文及考題設計／British Council 英協教育中心 Melissa Henry 　　中譯／陳怡君 （中央社編譯）

Has it been your dream to see the Aurora Lights? Scientists expect that 2016 will be the last year to easily see the Aurora Lights until 2023, so hurry before you miss your chance!

看極光是你一直以來的夢想嗎？科學家預測在2023年以前，2016年是容易看到極光的最後一年， 因此在你錯失機會前最好趕快！

The Aurora Borealis (in the Northern hemisphere) and Aurora Australis (in the Southern hemisphere) are colorful lights that appear in the sky. They are caused when the sun has a large explosion and thrusts charged particles into space. These particles reach Earth but the atmosphere protects Earth and slows down the particles. They then cause a sudden change in Earth’s magnetic field when they collide with the gas molecules in the atmosphere. The atmosphere molecules become excited which therefore makes them unstable and are forced to release its extra energy as electric currents, or light. Each gas in the atmosphere (oxygen, nitrogen, etc.) emits a different color of light when excited, which is why the Aurora Lights have the various blues, greens, yellows and reds.

（位於北半球的）北極光與（位於南半球的）南極光是在天空出現的七彩光芒，極光是在太陽表面發生磁爆時所產生，太陽在太空釋放出帶電粒子來到地球，當這些粒子抵達地球時，地球的大氣層能緩衝這些粒子、以達到保護地球的作用。

當粒子與大氣分子在大氣層碰撞後，地球磁場會突然改變，讓大氣分子處於不穩定的激發狀態， 並被迫釋放出電流、光等多餘能量。當大氣層中的氣體（氧、氮等）受到激發時，會散發出不同顏色，這也是為什麼極光有各種不同的藍、綠、黃、紅等顏色。

The lights happen in cycles and scientists started counting them in 1755. The sun is currently on its 24th sunspot cycle, which is measured by the number of sunspots visible on the sun. Within the cycle there are sunspot maximums and minimums, which correspond to how easily it is to see the lights. Some relate the sunspot cycle to a ‘heartbeat’, meaning that the sun beats every 10 to 12 years and this is what causes the explosions on the sun and therefore the lights.

極光的出現與太陽活動週期有關，科學家從1755年開始統計，目前太陽活動處於第24個太陽黑子週期，依據可看見的太陽黑子數估算。週期內有黑子數最大值與最小值，這和見到極光的難易度有關。有些科學家將太陽黑子週期比喻成「心跳」，意味太陽每10年至12年跳動一次，每一次的跳動造成太陽表面爆炸，也因此出現極光。

The 24th cycle maximum has already passed in April 2014 and the cycle is on its way to its end. Although this cycle has been a relatively weak one in comparison to those in the past, scientists suggest traveling this year to see the lights because the sun will soon enter its usual dormant period. However, there is also a possibility of a hibernation period, or a Grand Solar Minimum, in the upcoming years.

第24個黑子週期已經在2014年4月達到頂峰，現正逐漸進入尾聲。雖然這個週期和過去相比較為衰弱，但由於太陽很快將進入休眠期，科學家仍建議今年是適合賞極光的時機。不過未來幾年還是可能出現休眠，意即「太陽活動極小期」。

It is recommended to see the lights during the equinox months of September and March, but they can be seen from October through February in the Northern hemisphere. You will also need to stay away from light pollution and stay awake into the night as they are typically only visible from dusk to dawn. Most people choose Scandinavia, Greenland, Canada, Alaska, or Russia to see the lights, but they can also be seen in the far northern parts of Scotland, Wales, England, and Northern Ireland! Before going to any destination to see the lights, scientists recommend checking the geomagnetic activity to have a higher promise of electric activity in the night sky.

建議觀賞極光的季節是9月和3月的秋分與春分時節，但在北半球可以從10月一路看到2月，同時得避開光害，還得在夜晚保持清醒，因為一般來說只有從黃昏到黎明時分才看得到。大多數人選擇去斯堪地那維亞、格陵蘭島、加拿大、阿拉斯加或俄羅斯看極光，但在蘇格蘭的遠北地區、威爾斯、英格蘭與北愛爾蘭也能看得到。在前往任何目的地看極光前，科學家建議先查看地磁活動，以提高看到夜晚天空「放電」的機會。

The Aurora Lights have long been thought of as one of the wonders of the world and have drawn millions of tourists in high hopes of seeing the dancing lights. If you want to catch this current sunspot cycle, you will need to arrange your travel sooner rather than later, or you will have to wait for the next heartbeat of the sun.

極光一直以來被視為世界奇景，至今吸引數百萬名高度期望目睹光之舞的遊客。如果你想把握目前的太陽黑子週期，就得盡早安排旅程，否則就得等到太陽的下一次「心跳」。(完)

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