You might have often heard the term aurora borealis but what is an aurora?
An aurora is nothing but beautiful light shows in the sky. One can witness them near the North and the South Pole. If you witness it at the North Pole, it is aurora borealis or northern lights. In the South Pole, it is called aurora australis or the southern lights.
The Sun’s role
Now, even though auroras are best seen at night. they are actually caused by the Sun. Here’s how: The Sun sends to Earth heat light and lots of energy and other small particles. (But the Sun doesn’t always send the same amount of energy towards Earth.) Since the Earth is surrounded by a protective magnetic field, we do not experience the presence of most of these energy and small particles. Constantly streaming solar wind and solar storms are also sent by the Sun out into the space. During one such type of solar storm called a coronal mass ejection, the Sun sends out a huge bubble of electrified gas that can travel through space at high speeds. When this solar storm charges towards Earth, some of the energy can penetrate the magnetic field lines at the North and South Poles and enter the Earth’s atmosphere.
Electrically charged particles interact with the gases in the Earth’s atmosphere and result in beautiful displays of light in the sky.
Of green, blue and purple
If you have noticed an aurora or seen its photographs the colours in the sky are usually green, red, purple and blue. This is because the oxygen in our atmosphere gives off green and red light when mixed with the energy particles, and nitrogen glows blue and purple.
Picture Credit : Google
