Sunday, August 24, 2014


Our Sun constantly emits plasma which moves out in all directions at very high speeds and fills the entire solar system. The complex interaction between the Sun’s plasma atmosphere and its magnetic field gives rise to a wide range of fascinating and spectacular phenomena such as solar flares, filaments and prominences, coronal mass ejection (CME), spicules, sunspots.

Solar flares are huge outbursts of solar material, which are several thousand to million kilometers long. If we had some way of capturing all the energy emitted in one of the smallest solar flares, we would have enough energy to power the Earth for 1,000,000 years.

Filaments are dark, thread-like features that are seen in red light (H-
). They are dense, somewhat cooler, clouds of material. They are suspended above the surface of the sun by loops of magnetic fields. A prominence (left) is the same thing as a filament, except that prominences are seen projecting over the limb of the sun.

Filaments and prominences can remain relatively quiet and stable for days or weeks, but as the magnetic fields that support them change, they tend to erupt and rise off the sun over the course of a few minutes to hours. These are thousand to millions of kilometers wide and tall.

The fluctuation of the sun’s magnetic fields can cause a large portion of the outer atmosphere to expand rapidly, spewing a tremendous amount of particles into space. These large eruptions of magnetized plasma are called coronal mass ejections. CMEs are the most spectacular and potentially harmful manifestations of solar activity. Some of these eruptive events accelerate particles to very high energies, high enough to penetrate a space suit or the hull of a spacecraft and can cause severe disturbances in the geospace environment when they encounter Earth’s magnetic field. However, only about 1% of the CMEs produce strong SEP (solar energetic particles) events.

Spicules are little-understood yet very common features of the photosphere. They appear as small, sharp, jet-like spikes of material, throughout the chromosphere. They tend to last only a few minutes, but in the process they eject material off into the corona at speeds of 20-30 km/s.

Sunspots are cooler areas of the sun's photosphere. They also have very strong magnetic fields, up to 10,000 times that of Earth's - up to 3000 times that of the rest of the sun, and current sunspot theory holds that that it is the magnetic fields that cause the sunspots. Sunspots usually occur in groups of approximately 10, and the individual spots can be as large as the planet Earth. They are usually about 5,000 K (8,500 °F), which is 800 K (1,500 °F) cooler than the rest of the photosphere.

Watch video:
NASA | Firework Flare



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