Category Science

What are flares?

While prominences are analogous to ordinary flames, flares are analogous to sudden bursts of flame such as would happen if an ordinary fire were to pass over a stock of petrol. Flares are therefore similar to prominences, only more spectacular. Flares are so violent that they are usually ejected out of the Sun. A flare is seen as a short-lived (typically lasting a few minutes) burst of light. However, it gives out a variety of radiations from X-rays to radio waves, which may sometimes cause disturbances even on Earth.

What kind of disturbances can be caused on Earth by solar flares?

The radiation from solar flares may cause curtain-like auroral displays in the sky and interference in radio communication, by causing disturbances in the Earth’s atmosphere and magnetic field disruptions.

What is the energy released in a solar flare?

A force equal to about ten million hydrogen bombs.

What are solar filaments?

Smaller solar prominences in the form of streams and lops occurring in front of the Solar disc appear as dark lines ( since they are colder than surrounding area) and are known as filaments.

What are spicules?

Spicules are the eruptions occurring on the Sun’s surface due to the regular upwelling of super granules. Spicules are analogous to the eruptions on the surface of the water boiling in a vessel. Spicules rise up to about 10,000 km above the Sun’s surface.

What are prominences?

Prominences are gigantic geysers of gas which surge out of the Sun. Prominences may fall back into the Sun (sometimes in graceful loops) or they may be thrown out of the Sun and get dissipated. Prominences are analogous to the flames in a fire and can rise more than 1, 00,000 km above the Sun’s surface.

What are the disturbances that occur on the surface of the Sun due to the nuclear reactions within?

The nuclear reactions within the Sun cause tremendous upheavals inside the Sun, resulting in disturbances on the surface of the Sun. These disturbances usually take the form of granulation, spicules and prominences.

What is granulation?

Granulation refers to the wavy appearance of the Sun due to the fact that the surface of the Sun is in a state of constant agitation.

What are super granules?

Super granules are bubbles of gas rising very slowly from the interior of the Sun and breaking through the surface. A super granule may even take a million years to rise from the centre of the Sun to the surface.

However, once it breaks through the surface, it dissipates in less than half a day. A super granule is about 30,000 km wide. It is still tiny compared to the size of the Sun.

Is the material in the Sun uniformly homogeneous?

No. The Sun contains a central core where the nuclear reactions take place. The core is surrounded by a radiative zone through which the energy radiates outwards from the core. The next layer is the convective zone which is in constant turmoil and heat transfer takes place by convection. The final layer is the photosphere which is the outer shell of the Sun (which we see which radiates light, heat and other forms of energy into space.

The cross-section consists of the core, radiative zone and convective zone. The visible surface is the photosphere on which are seen the dark sunspots and the bright faculae. Above this lies the chromospheres, and then the hot rarefied corona. The stream of subatomic particles moving out through the corona into space is the solar wind.

What is the corona?

The corona refers to the outermost regions of the Sun’s atmosphere. The corona can be seen from Earth only during a total solar eclipse, or by using an occulter-a disc used on the telescope to block the view of the sun’s disc (photosphere).

Does the tidal effect act on the molten liquid core of the Earth?

The Earth is solid only over a thin portion of its surface. Most of the inner portion of the Earth is hot liquid material, which is also affected by the tidal forces in the same way as the oceans of water on the surface.

The tidal effect on the liquid core of the Earth influences geological activity such as earthquakes, volcanic eruptions and the gradual drifting apart of the continents.

Does the tidal effect apply to human beings on Earth?

Yes. Your weight on Earth will vary slightly decrease when the Moon is directly overhead.

What is the frequency of the ocean tides on Earth?

One high tide occurs approximately every 12.5 hours followed by a low tide.

What are spring tides?

Spring tides are the maximum tides. They occur when the Sun is in line with the Moon, resulting in a maximum combined tidal effect.

What are neap tides?

Neap tides are the minimum tides. They occur when the Moon, Earth and Sun from right angles, resulting in a minimum combined tidal effect.

Are spring tides and neap tides related to the seasons such as spring, summer, etc.?

No.