Our precious Atmosphere

[For why I began this series of posts in the first place, please check out this post :) ]

So it begins with skies, which I think is very apt, since the heavens were the source of awe and wonder since the dawn of humanity.

It first talks about Earth's atmosphere. We take it so much for granted that we forget just how precious it is. Without it, the Earth would be scorching hot like Venus, allowing no life. Without the perfect balance of gases like the 0.04% carbon dioxide that keeps us warm and the 99% nitrogen and oxygen that we need for living, we would have no breath to take and we would not have survived the extreme weathers if not for the greenhouse effect.

If we didn't have the atmosphere, we would not have protection against the UV rays, not to mention the 1.4 million meteroids that fall on Earth every day, as the chilling reality of the Moon reminds us.

The atmosphere also makes our days and nights so much more beautiful and richer. It makes our sky Blue, for the fact that blue rays from sunlight are scattered more easily than red rays due to an effect called Rayleigh Scattering. For the same reason, it makes our sunsets beautifully Orangy Red, because as the sunlight passes through the atmosphere at a low angle, the blue rays are scattered out, leaving red rays to reach our eyes. How wonderful!

Though the atmosphere is but a thin "crust" relative to the Earth, it is usually divided into 4 main parts:

1. Troposphere (0-17km above surface) - where almost all the action is, the planes, the mountains, the rain and the thunder

2. Stratosphere (~17-50km above surface) - where weather balloons reach and where the ozone layer is.

3. Mesosphere (~50-85km above surface) - where meteoroids burn up

4. Ionosphere or Thermosphere (~85-690km above surface) - where the air is ionized and so reflects radio waves thereby allowing our electronics to function, and interacts with solar winds, creating beautiful things like the auroras. It is also where the space station is. Beyond the Karma Line at 100km, it is considered Outer Space.

The atmosphere surely is a gift to life, let us be thankful for having it!