Aurora
Definition
Aurora is a natural light display in Earth's sky, predominantly seen in high-latitude regions around the Arctic and Antarctic. It is caused by the interaction between charged particles from the Sun and Earth's magnetic field and atmosphere.
5 Must Know Facts For Your Next Test
- Auroras are most commonly observed near the polar regions, referred to as Aurora Borealis in the northern hemisphere and Aurora Australis in the southern hemisphere.
- The phenomenon occurs when solar wind particles collide with gases like oxygen and nitrogen in Earth's atmosphere, causing them to emit light.
- The color variations in auroras are due to different gases; for example, green auroras are typically caused by oxygen at lower altitudes while red auroras come from oxygen at higher altitudes.
- Auroral activity increases during periods of high solar activity such as solar flares or coronal mass ejections (CMEs).
- In addition to being visible from Earth, auroras can also be detected via satellite imagery and other space weather monitoring tools.
Review Questions
- What causes the formation of an aurora?
- Why do auroras exhibit different colors?
- How does solar activity influence auroral displays?
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Related terms
Solar Wind: A stream of charged particles released from the upper atmosphere of the Sun, which interacts with Earth's magnetic field to create phenomena like auroras.
Magnetosphere: The region around Earth dominated by its magnetic field, protecting it from solar wind but also channeling these particles towards the poles where they cause auroras.
Coronal Mass Ejection (CME): A significant release of plasma and magnetic field from the Sun's corona that can enhance geomagnetic storms and increase auroral activity when it reaches Earth.
