Relevance: GS-1: Important Geophysical phenomena
Key phrases: Coronal Mass Ejection, geomagnetic storm, solar maxima, solar minima, solar storms, radiation
Why in News?
- A geomagnetic storm triggered by a large burst of radiation from the sun has disabled at least 40 of the 49 satellites newly launched by SpaceX as part of its Starlink internet communications network, the company said.
What is Coronal Mass Ejection?
- A coronal mass ejection (CME) or Solar storm is a significant release of plasma and accompanying magnetic field from the Sun's corona into the solar wind. CMEs are often associated with solar flares and other forms of solar activity, but a broadly accepted theoretical understanding of these relationships has not been established.
- If a CME enters interplanetary space, it is referred to as an interplanetary coronal mass ejection (ICME). ICMEs are capable of reaching and colliding with Earth's magnetosphere, where they can cause geomagnetic storms, aurorae, and in rare cases damage to electrical power grids.
- Near solar maxima, the Sun produces about three CMEs every day, whereas near solar minima, there is about one CME every five days
A geomagnetic storm is a major disturbance of Earth's magnetosphere that occurs when there is a very efficient exchange of energy from the solar wind into the space environment surrounding Earth. If a CME collides with the Earth, it causes a geomagnetic storm.
Ar solar storms dangerous to humans on Earth’s surface?
Solar storms aren’t dangerous to humans on Earth’s
surface. These storms are awesome to contemplate, but they cannot harm
our human bodies as long as we remain on the surface of Earth, where
we’re protected by Earth’s blanket of atmosphere. Remember, there’s
every reason to believe that storms on the sun have been happening for
billions of years, since the sun and Earth came to be. If that’s so, then
all life on Earth evolved under their influence. So, Still, solar storms –
and their effects – are no problem for us on Earth’s surface. Earth’s
atmosphere and magnetosphere protect our human bodies from the effects
of solar flare.
But solar storm human is dangerous to humans in space. Very
high-energy particles, such as those carried by CMEs, can cause radiation
poisoning to humans and other. They would be dangerous to unshielded
astronauts and astronauts traveling to the moon. Large doses could be fatal.
Effects of Solar storm or CMEs on Earth:
- Not all solar flares reach Earth, but solar flares/storms, solar energetic particles (SEPs), high-speed solar winds, and coronal mass ejections (CMEs) that come close can impact space weather in near-Earth space and the upper atmosphere.
- Solar storms can hit operations of space-dependent services like global positioning systems (GPS), radio, and satellite communications. Geomagnetic storms interfere with high-frequency radio communications and GPS navigation systems. Aircraft flights, power grids, and space exploration programmes are vulnerable. Ex. A geomagnetic storm triggered by a large burst of radiation from the sun has disabled at least 40 of the 49 satellites newly launched by SpaceX as part of its Starlink internet communications network.
- CMEs, with ejectiles loaded with matter travelling at millions of miles an hour, can potentially create disturbances in the magnetosphere, the protective shield surrounding the Earth. Astronauts on spacewalks face health risks from possible exposure to solar radiation outside the Earth’s protective atmosphere.
- Energetic protons released by a CME can cause an increase in the number of free electrons in the ionosphere, especially in the high-latitude Polar Regions. The increase in free electrons can enhance radio wave absorption, especially within the D-region of the ionosphere, leading to polar cap absorption events.
- Effective and high electrical currents that come along the Earth’s surface at the time of auroral events disrupt electric power grids. Ex. A CME caused a power failure in Québec, as well as across parts of the northeastern U.S. In this event, the electrical supply was cut off to over 6 million people for nine hours.
- The largest recorded geomagnetic perturbation, resulting presumably from a CME, was the solar storm of 1859. Also known as the Carrington Event, it disabled parts of the at the time newly created United States telegraph network, starting fires and shocking some telegraph operators.
Way forward:
- These are the natural phenomenon and we cannot stop it. Prediction and prevention is the only option to reduce the effect of these storms.
- For example at the Space Weather Prediction Centre – continually monitor the sun, both from space and from Earth’s surface. When a solar storm with the potential to affect Earth takes place, they see it and rises an alert.
- When a big CME is on its way, it is possible for satellites to shut their systems off briefly, and thereby remain safe. Likewise, with advance warning, Earth-based power grids can be reconfigured to provide extra grounding.
- Governments and scientists are beginning to pay more attention to this issue, with an eye to creating systems and procedures to help withstand such powerful effects from the sun.
Source: Live mint
Mains Question:
Q. What do you understand by Coronal Mass Ejection and how does it affect the earth? Critically analyse. (200 words)
