Here is a second interesting topic I came across this past week! Though mostly everyone has either seen the Northern Lights or heard of their existence, few people actually understand how this comes about. What gives them shape, color, and vibrancy? As engineers, we look to constantly learn and tackle new problems in the hope we can understand all that we come into contact with.
In my ASTE 330 course, we briefly talked about the Northern Lights and caught my interest into just how exactly this phenomenon occurred. It turns out, as the Sun constantly spews out solar wind and cosmic radiation omni-directionally, some protons shoot towards the Earth. As it nears the Earth, the protons are drawn to the polar regions by the Earth’s magnetic field. This causes the Earth to become surrounded by a layer of hot plasma and diverts some of the solar wind. These excess high velocity protons become energized entering the atmosphere and collide with electrons. When the electrons collide with other atoms they release energy in the form of light. These are the Northern Lights. Now, depending on the atoms and ions that are colliding, different colors will present themselves. Green corresponds to Oxygen, Red to Hydrogen, and Blue to Nitrogen, while the shapes are determined by the speed, density, and magnetic field trail. As the Earth rotates and orbits the Sun, variations in the shapes, and color patterns emerge.
In addition, because the Earth’s orbit is not perfectly circular, there are times when it is closest and farthest from the Sun. These are commonly thought of to be the seasons with summer being when the Earth is closest to the Sun and winter when it is the farthest. This is incorrect. The Earth’s seasons actually are because of its 23.5 degree tilt! When the Earth is tilted towards the Sun, it experiences more direct radiation. This is when summer occurs. Likewise when it is tilted away, the angle to the Sun causes the radiation to be spread over a larger area and we experience winter.
These questions that come from class are not difficult to understand or find, but in taking the extra step to learn more than expected, you not only put yourself ahead, but also develop as a person. I recommend you try and be the person who goes the extra mile! Along the way you may learn something truly amazing!