Aurorae in high-latitude countries
- November 7, 2021
- Posted by: OptimizeIAS Team
- Category: DPN Topics
Aurorae in high-latitude countries
Subject – Science and Tech
Context – The Sun lights up aurorae in high-latitude countries
- A solar flare that occurred on the Sun triggered a magnetic storm which scientistshad predicted will arrive at the Earth in the early hours of November 4, and they said that the magnitude of this storm would be such as to trigger spectacular displays of aurora (the coloured bands of light seen in the North and South poles) in the high-latitude and polar regions.
- These observations are taken at Lagrange Point L1.
Sunspots seed storms
- The solar magnetic cycle that works in the deep interior of the Sun creates regions that rise to the surface and appear like dark spots. These are the sunspots. Solar flares are highly energetic phenomena that happen inside the sunspots.
- In a solar flare, the energy stored in the Sun’s magnetic structures is converted into light and heat energy.
- This causes the emission of high energy x-ray radiation and highly accelerated charged particles to leave the Sun’s surface.
- Sometimes solar flares also cause hot plasma to be ejected from the Sun, causing a solar storm, and this is called Coronal Mass Ejection (CME). Coronal Mass Ejections can harbour energies exceeding that of a billion atomic bombs.
- The energy, radiation and high-energy particles emitted by the flares can affect Earth-bound objects and life on Earth – it can affect the electronics within satellites and affect astronauts.
- Very powerful Earth-directed coronal mass ejections can cause failure of power grids and affect oil pipelines and deep-sea cables. They can also cause spectacular aurorae in the high-latitude and polar countries.
- The last time a major blackout due to a coronal mass ejection was recorded was in 1989 – a powerful geomagnetic storm that took down the North American power grid, plunging large parts of Canada into darkness and triggering spectacular aurorae beyond the polar regions.
Lagrange Point 1
- Lagrange Points, named after Italian-French mathematician Josephy-Louis Lagrange, are positions in space where the gravitational forces of a two-body system (like the Sun and the Earth) produce enhanced regions of attraction and repulsion.
- The L1 point is about 1.5 million km from Earth, or about 1/100th of the way to the Sun.
- L1 refers to Lagrangian/Lagrange Point 1, one of 5 points in the orbital plane of the Earth-Sun system.
- These can be used by spacecraft to reduce fuel consumption needed to remain in position.
- A Satellite placed in the halo orbit around the Lagrangian point 1 (L1) has the major advantage of continuously viewing the Sun without any occultation/ eclipses.
- The L1 point is home to the Solar and Heliospheric Observatory Satellite (SOHO), an international collaboration project of National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA).
- An Aurora is a display of light in the sky predominantly seen in the high latitude regions (Arctic and Antarctic). It is also known as a Polar light.
- They commonly occur at high northern and southern latitudes, less frequent at mid-latitudes, and seldom seen near the equator.
- While usually a milky greenish color, auroras can also show red, blue, violet, pink, and white. These colors appear in a variety of continuously changing shapes.
- Auroras are not just something that happens on Earth. If a planet has an atmosphere and magnetic field, they probably have auroras.