Solar flares

Solar flare

A solar flare is a sudden brightening observed over the Sun surface or the solar limb, which is interpreted as a large energy release of up to 6 × 10²⁵ joules of energy (about a sixth of the total energy output of the Sun each second). The flare ejects clouds of electrons, ions, and atoms through the corona into space. These clouds typically reach Earth a day or two after the event.The term is also used to refer to similar phenomena in other stars, where the term stellar flare applies.

Solar flares affect all layers of the solar atmosphere (photosphere, chromosphere, and corona), when the medium plasma is heated to tens of millions of kelvins and electrons, protons, and heavier ions are accelerated to near the speed of light. They produceradiation across the electromagnetic spectrum at all wavelengths, from radio waves to gamma rays, although most of the energy goes to frequencies outside the visual range and for this reason the majority of the flares are not visible to the naked eye and must be observed with special instruments. Flares occur in active regions around sunspots, where intense magnetic fields penetrate the photosphere to link the corona to the solar interior.

Hazards

Solar flares strongly influence the local space weather in the vicinity of the Earth. They can produce streams of highly energetic particles in the solar wind, known as a solar proton event, or "coronal mass ejection" (CME). These particles can impact the Earth's magnetosphere (see main article at geomagnetic storm), and present radiation hazards to spacecraft, astronauts and cosmonauts.

Massive solar flares have been known to knock out electric power for extended periods of time.

The soft X-ray flux of X class flares increases the ionization of the upper atmosphere, which can interfere with short-wave radio communication and can heat the outer atmosphere and thus increase the drag on low orbiting satellites, leading to orbital decay. Energetic particles in the magnetosphere contribute to theaurora borealis and aurora australis. Energy in the form of hard x-rays can be damaging to spacecraft electronics and are generally the result of large plasma ejection in the upper chromosphere.

The radiation risks posed by coronal mass ejections are a major concern in discussions of a manned mission to Mars, the moon, or other planets. Energetic protons can pass through the human body, causing biochemical damage, and hence present a hazard to astronauts during interplanetary travel. Some kind of physical or magnetic shielding would be required to protect the astronauts. Most proton storms take two or more hours from the time of visual detection to reach Earth's orbit. A solar flare on January 20, 2005 released the highest concentration of protons ever directly measured, taking only 15 minutes after observation to reach Earth, indicating a velocity of approximately one-third light speed, giving astronauts as little as 15 minutes to reach shelter.

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Material phases

Materials have different states. The state of a material depends on the temperature. Let's start from coldest one and keep increasing temperature.

Solid: Solid is one of the three classical states of matter. Solid is the coldest state of material, Meaning the average kinetic energy of molecule is lowest in this state. It's property are rigidity in shape and volume. Reason being tightly compact molecules. Unlike fluid solid doesn't flow.

There are different kinds of solid which are crystalline and amorphous. Which are caused by alignment of molecules in solid.

When solid is heated it changes into liquid. Sometimes solid changes directly to gas while heating. This process is called Sublimation.






Liquid: Liquid is one of the three classical states of matter. Liquid is the warmer state of material than solid, Meaning the average kinetic energy of molecule is higher than of solid. It's property are rigidity in volume. But the shape of the liquid can change. It takes the shape of the container. Liquid and gas collectively are called fluid.

When solid is heated enough. Solid melts to form liquid. Liquid can be cooled to form solid.


Gas: Gas is one of the three classical states of matter. This is the hottest state of material among classical states. The volume and shape of gas can be changed. Gas are usually invisible. The void between molecules is so big that photos will not be reflected while passing through gas so we can't usually see them.

No gas exists at absolute zero temperature (-273.15C). When liquid is heated it boils and becomes gas. But even below boiling temperature a fraction of the liquid is always evaporating (turning to gas). Cooling gas changes it into liquid and than into solid.

Plasma: Plasma in not a classical state of material. It is a lot like gas so it used to classified as gas. But more accurately plasma is ionized gas. It's basic properties are same as gas but plasma is conductive while gas isn't. In electric and magnetic field plasma acts differently than gas. Although ignored for so long, plasma is the most common form of material in the universe.

When gas is heated high enough the atoms of gas looses electrons and the gas become ionized. Cooling will result in gas as expected.

 Although the material can have many different states, same material has same chemical properties. Only physical properties changes.