The Auroras Reading Answers

THE AURORAS

Auroras, also known as ‘polar lights’, are a natural display of lights in the sky of Arctic and Antarctic regions. This is a breathtaking show of lights that can be in yellow, white, green or red. When this phenomenon occurs in the northern hemisphere, it is called ‘Northern lights’ or ‘aurora borealis’ and in the southern hemisphere, it is known as ‘Southern lights’ or ‘aurora australis’.

From ancient times, humans have been enthralled by this mysterious phenomenon of waning and waxing of the auroral lights. This has given birth to folktales revolving around mythological creatures and has also influenced art, religion and history. The oldest auroral citation dates back to 2600 B.C. in China. It was Fu-Pao, mother of Shuan-Yuan of the Yellow Empire, who saw strong lights moving about the star Su in the Bei-Dou constellation illuminating the whole area. Much later, in 1570 A.D., a drawing recorded the aurora, portraying it as candles burning in the sky. It was Galileo Galilei, who coined the term ‘aurora borealis’ in 1619 A.D. after the Roman goddess of morning, Aurora. However, he wrongly believed that the auroras were caused by the reflection of sunlight from the atmosphere.

So what causes auroras? The sun discharges a lot of energy and small particles continuously through solar wind and sometimes through solar storms. When these energetic particles interact with the atoms or molecules of oxygen, nitrogen or other elements present in the upper atmosphere of the earth, it results in the spectacular show of lights. These interactions usually take place in high latitudes, at around 70 degrees, in oval-shaped zones surrounding the magnetic poles of the earth. When there is low solar activity, the aurora zones move towards the poles. When the solar intensity increases, the auroras sometimes stretch to the middle latitude areas. For example, the northern lights have been observed as far south as 40 degrees latitude in the US. Typically, auroral emissions occur at 100 km altitudes, but they can occur anywhere between 80 to 250 kilometres above the earth.

The sunspots and the solar storms happen every eleven years, and they cause the most breathtaking display of the aurora borealis. In 2013, there was a peak in the solar cycle, but this solar peak was the weakest in the century. Ron Turner, Senior Science Advisor to NASA’s programme on Innovative Advanced Concepts, says, ‘This solar cycle continues to rank among the weakest on record.’ There have been as many as 22 full cycles ever since 1749 when the documentation of the ebb and flow of the sun's activity began. Researchers are keen on monitoring space weather events because they can affect the orbiting space ships and disturb the power grids and the communication links on Earth. Scientists are also investigating how fluctuations in solar activity affect the weather on earth.

Alaska and northern Canada are the ideal locations for a view of the northern lights. Other good viewing locations are Sweden, Finland and Norway. When the solar flares are especially active, the lights can be clearly seen in places such as the north of Scotland and sometimes even northern England. 

Questions 1-5

Choose the correct letter, A, B, C or D.

1. Auroras are named according to
   1. Their colours.
   2. Their location.
   3. The intensity of lights.
   4. The time of occurrence.
2. People’s attraction towards auroral lights has
   1. Created several stories.
   2. Developed into various artforms.
   3. Created many mysteries.
   4. Led to historical events.
3. Galileo Galilei was the first to
   
   1. Draw the phenomenon.
   2. Observe the phenomenon.
   3. Name the phenomenon.
   4. Believe in the phenomenon.
4. Auroras occur 
   
   1. Mostly during solar storms.
   2. Due to interaction between energetic particles and atmospheric gases. 
   3. Exclusively at high latitudes.
   4. Usually at middle latitudes.
5. In 2013,
   1. The most spectacular aurora was observed.
   2. Solar activity was at its lowest.
   3. No solar activity was recorded.
   4. The weakest solar peak was recorded.

1. b. Their location 

Explanation: Paragraph 1 - When this phenomenon occurs in the northern hemisphere, it is called ‘Northern lights’ or ‘aurora borealis’ and in the southern hemisphere, it is known as ‘Southern lights’ or ‘aurora australis’.

2. a. Created several stories 

Explanation: Paragraph 2 - From ancient times, humans have been enthralled by this mysterious phenomenon of waning and waxing of the auroral lights. This has given birth to folktales ... 

3. c. Name the phenomenon 

Explanation: Paragraph 2 - It was Galileo Galilei, who coined the term ‘aurora borealis’ in 1619 A.D., ...

4. b. Due to interaction between energetic particles and atmospheric gases 

Explanation: Paragraph 3 - When these energetic particles interact with the atoms or molecules of oxygen, nitrogen or other elements present in the upper atmosphere of the earth, it results in the spectacular show of lights.

d. The weakest solar peak was recorded

Explanation: Paragraph 4 - In 2013, there was a peak in the solar cycle, but this solar peak was the weakest in the century.