Headline : Note on Solar storm
- The surface of the Sun is a very busy place.
- It has electrically charged gases that generate areas of powerful magnetic forces.
- These areas are called magnetic fields .
- The Sun’s gases are constantly moving, which tangles, stretches and twists the magnetic fields.
- This motion creates a lot of activity on the Sun’s surface, called solar activity.
- Sometimes the Sun’s surface is very active.
- Other times, things are a bit quieter.
- The amount of solar activity changes with the stages in the solar cycle .
- Solar activity can have effects on Earth, so scientists closely monitor solar activity every day.
- Few forms of solar activities are:
- Solar flares
- Coronal mass ejections
- High-speed solar wind
- Solar energetic particles
- All these solar activities are driven by the solar magnetic field.
- Sunspots are areas that appear dark on the surface of the Sun.
- These appear dark because they are cooler than other parts of the Sun’s surface.
- The temperature of a sunspot is still very hot that is around 6,500 degrees Fahrenheit.
- Sunspots are relatively cooler because these form at areas where magnetic fields are particularly strong.
- These magnetic fields are so strong that they keep some of the heat within the Sun from reaching the surface.
- These were first known to be occurring in 1859.
- The magnetic field lines near sunspots often tangle, cross, and reorganize.
- This can cause a sudden explosion of energy called a solar flare.
- More sunspots lead to more frequently occurring solar flares.
- Solar flares release a lot of radiation into space.
- Flares are the largest explosive events of our solar system.
- These are seen as bright areas on the sun and these can last from minutes to hours.
- Solar flare is seen by the photons (or light) it releases, at almost every wavelength of the spectrum.
- Flares are also sites where particles (electrons, protons, and heavier particles) are accelerated.
- Solar flares are sometimes accompanied by a coronal mass ejection (CME).
- CMEs are huge bubbles of radiation and particles from the Sun.
- These explode into space at very high speed when the Sun’s magnetic field lines suddenly reorganize.
- Solar flares cannot typically be detected by the naked eye from the surface of the earth.
- The primary ways to monitor flares are by x-rays and optical light.
- Solar flare activity can vary from several per day to only a few a month, depending mostly upon the overall activity of the Sun as a whole.
- Solar flares are typically classified as A, B, C, M or X depending upon the degree of their peak flux.
Effects of solar flares
- Solar flares impact the Earth only when these occur on the side of the sun facing the Earth.
- Because flares are made of photons, these travel out directly from the flare site, so if we can see the flare, we can be impacted by it.
- When charged particles from a CME reach areas near the Earth, these can trigger intense lights in the sky, called auroras.
- Radiations released from the solar flare can:
- Interfere with radio communications on the Earth
- Disrupt power utility grids, which at their worst can cause electricity shortages and power outages
- Knockout satellites
- Effect spark stunning displays of the Northern Lights
- The Sun is a magnetic variable star at the center of our solar system that drives the space environment of the planets, including the Earth.
- The distance of the Sun from the Earth is approximately 93 million miles.
- At this distance, light travels from the Sun to the Earth in about 8 minutes and 19 seconds.
- The Sun has a diameter of about 865,000 miles, about 109 times that of Earth.
- Its mass is about 330,000 times that of Earth and accounts for about 99.86% of the total mass of the Solar System.
- About three quarters of the Sun’s mass consists of hydrogen, while the rest is mostly helium.
- Less than 2% consists of heavier elements, including oxygen, carbon, neon, iron, and others.
- The Sun is neither a solid nor a gas but is actually plasma.
- This plasma is tenuous and gaseous near the surface, but gets denser down towards the Sun’s fusion core.
Layers of Sun
- It can be divided into six layers.
- From the center out, the layers of the Sun are as follows:
- The solar interior composed of the core (which occupies the innermost quarter or so of the Sun’s radius)
- Radiative zone
- Convective zone
- Photosphere (visible surface)
- Corona (outermost layer)
- The energy produced through fusion in the Sun’s core powers the Sun and produces all of the heat and light that we receive here on the Earth.
- The Sun, like most stars, is a main sequence star and thus generates its energy by nuclear fusion of hydrogen nuclei into helium.
- In its core, the Sun fuses 430–600 million tons of hydrogen each second.
- The Sun’s hot corona continuously expands in space creating the solar wind, a stream of charged particles that extends to the heliopause at roughly 100 astronomical units.
- The bubble in the interstellar medium formed by the solar wind, the heliosphere, is the largest continuous structure in the Solar System.
Section : Science & Tech