Auroras:
- Auroras are a natural light display in the sky, predominantly seen in the high-latitude regions (around the Arctic and Antarctic).
- It is called aurora borealis or northern lights near the North Pole.
- It is called aurora australis or southern lights near the South Pole.
- Cause: It is caused by the interaction of charged particles from the sun with the Earth's atmosphere.
- Aurora borealis is typically seen as a faint glow in the sky, but it can sometimes be very bright and colourful.
What makes this happen?
- Apart from heat and light, the Sun also releases energetic charged particles. The protective magnetic field around Earth shields us from most of the energy and particles.
- However, the Sun does not send the same amount of energy all the time. There is a constant streaming solar wind and there are also solar storms.
- During one kind of solar storm called a coronal mass ejection, the Sun ejects a huge bubble of electrified gas that can travel through space at high speeds.
- When a solar storm comes toward Earth, some of the energy and small particles can travel down the magnetic field lines at the north and south poles and enter into the Earth's atmosphere.
- There, the particles interact with gases in Earth’s atmosphere and result in beautiful displays of light in the sky.
- Oxygen gives off green and red light.
- Nitrogen glows blue and purple.
Do other planets get auroras?
- Auroras do not just happen on Earth. If a planet has an atmosphere and magnetic field, they probably have auroras.
- Incredible images of auroras have also been captured on Jupiter, Saturn, Uranus and Neptune.