Aurora Australis - Cited Below
How are Auroras Created? - Auroras are created by something called a coronal mass ejection, when the sun's outer layer spurts out a small amount of electrified gas. The sun gradually loses mass in the form of high speed electrons and protons. (The sun has lost less than 0.1% of its mass this way over its 4.6 billion year life). This is called a solar wind or solar storm. As a solar storm comes toward us, the magnetosphere of our planet protects us from the full blow, but some energy and small particles travel down the magnetic field lines at the poles into Earth's atmosphere. Once these particles are in our atmosphere, they collide with gases and gain energy. As they relax, they release photons of specific wavelengths, forming the aurora borealis and australis. Photons are light particles.
Colors - Auroras turn different color when they react to different gases in our atmosphere. When electrons and protons react with oxygen particles, they turn red or green. When they react with nitrogen particles, they turn orange, blue or purple. For example, the Aurora Borealis is mostly green, meaning the electrons in it react mostly with oxygen. There can also be auroras on other planets, as long as they have an atmosphere and magnetic field, and solar storms can reach them. For example, this aurora on Saturn:
Aurora on Saturn - Cited Below
Where they can best be seen - The Aurora Borealis and Australis can best be seen near the magnetic poles, for example Alaska (the Aurora Borealis), because that is where the electrons from the sun enter. They travel along the magnetic field lines to enter the atmosphere. But since the magnetic poles of Earth are not exactly aligned with the geographic poles, neither are the auroras. The Aurora Borealis, or the Northern Lights, can mostly be viewed from Siberia, Scandinavia, Tasmania, South Greenland and North Canada and Alaska. The Aurora Australis, or Southern Lights, can mostly be viewed from Antartica.
Did You Know? - Auroras are so bright that they are visible from space. There have been many pictures of auroras on Earth taken from the International Space Station (ISS). Also, auroras on other planets are visible from space, viewed from spacecrafts sent towards them.
Summary - A general summary of how auroras are created is that auroras are created because of solar particles - electrons and protons - reacting with gases in our atmosphere. The color of the aurora depends on the gas it reacts with. They can best be seen from the magnetic poles because that is where the sun's particles enter from, following the magnetosphere's magnetic field lines.
- Erickson, Kristen. "What is an Aurora." NASA Space Place. NASA, 10 Mar. 2017. Web. 10 Mar. 2017.
- "Auroras - Paintings in the Sky." Auroras. Auroras, 19 June 2001. Web. 12 Mar. 2017.
- "The Solar Wind." Hyperphysics. Hyperphysics, n.d. Web. 10 Mar. 2017.
- Emspak, Jesse. "Northern Lights: 8 Dazzling Facts About Auroras ." LiveScience. N.p., 27 Oct. 2014. Web. 13 Mar. 2017.
- Potter, Bec. Aurora Australis Captured over Ararat, Victoria. 2015. Ararat, Victoria.