31 August 2008

Picture of the Month - August 2008



Do you see a Sun Spot on the Sun??? Click on the Picture to see it in a larger resolution. You can now clearly see that its not a Sun Spot but a space Station. It is the International Space Station (ISS) trasiting the Sun. As the ISS moves around the Earth, the space station (very rarely) appears to move across the surface of the Sun as in this Picture.

16 August 2008

Solar Eclipse

If you had read my previous post on Occultation you would have known that Solar Eclipse is also an Occultation. Solar Eclipse is nothing but the effect of Moon occulting the Sun.

The Moon revolves around the Earth just as Earth revolves around the Sun. Moon takes approximately 30 days to move around the Earth. During this revolution the Moon comes in between the Earth and the Sun once every 30 days which we call as New Moon. On certain New Moon days the Moon is exactly in between the Earth and the Sun such that the Moon blocks the sun light, thus creating a shadow on the surface of the Earth. The Moon appears to move across the surface of the Sun when viewed from those shadowed area. This phenomenon is known as Solar Eclipse.

The Shadow of the Eclipse on the Earth


There are three types of Solar Eclipse.

Partial Solar Eclipse:

When viewed from Earth the Moon blocks a part of the Sun and does not block it completely. This is known as Partial Solar Eclipse. The region under the penumbra experiences the Partial Solar Eclipse. Partial Solar Eclipse is not dangerous to view at all. But continuous view of Sun can create some damage to the eye and hence it can be viewed through any Sun Glass.


A view of Partial Solar Eclipse


Total Solar Eclipse
:

This occurs when the Moon completely blocks the Sun letting no light reach the Earth. The region under the umbra experiences the Total Solar Eclipse. The total Solar Eclipse begins with the partial eclipse with the Moon moving slowly across the surface of the Sun until it completely blocks the Sun. For about a minute the sky would be dark. Then as the Moon continues to move a bright light comes out from one end of the Sun which looks like a Diamond Ring and hence it is called so. Since a great amount of light comes in within a fraction of a second it can blind us permanently when tried to view. Total Solar Eclipse can be viewed using a special google created for the eclipse.


Formation of Total Solar Eclipse



The Diamond Ring Effect


Annular Eclipse:

This is the most rarest of all eclipses. This occurs when the Moon is farthest from Earth during the eclipse. This occurs when the shadow of the Sun could not reach the Earth or when the Earth is at antumbra. The Moon appears smaller than the sun when viewed from Earth and hence at a Total eclipse the Moon does not block the Sun entirely but only the center portion of it. The outer surface of the Sun is clearly seen.


Annular Eclipse


The following image explains more about the Umbra, Penumbra and Antumbra and the reason why we experience partial, total or annular eclipse.

Umbra, Penumbra and Antumbra

India experienced a Partial Solar Eclipse as recently as August 1st, 2008. And that was the day I heard so many rumors about the Eclipse which were not true. I tried telling my friends but none believed me. But I would like to share it to all so that none would believe such rumors next time.

Some of them were very scared that staying outside on such days will affect their health. The only trouble Solar Eclipse gives us is blinding us only when we look at the Sun at a perfect Total Solar Eclipse. Watching a Partial Solar Eclipse is like watching the Sun any other day which does not create much damage except by continuous looking at it.

One such friend of mine didn't have his lunch saying that he heard that people should not eat during a Solar Eclipse in a News Channel. Later when I viewed the same channel I realized that it was a superstitions that was brought out by the News Channel. In reality Solar Eclipse does not change our body mechanism by any way and hence we need not lose our appetite on the eclipse day.

The best of all was a conversation between two girls that i over heard as I was walking on the road. As it started drizzling i heard them talk.
Girl 1: Oh God!! Its about to rain.
Girl 2: It cant rain today. Its Solar Eclipse.
What's Solar Eclipse got to do with the clouds or rain? Its simply rumors and people need not be fooled by such things. Solar Eclipse does not create any damages to us other than blinding us.

The next Total Solar eclipse in India occurs on January 26th, 2009 and the next Annular Eclipse occurs on January 15th, 2010.