Saturday 7 February 2015

Rainbows and more...

Hello again! 
Have you ever wondered how a rainbow occurs? I know I have many times. By the time you finish reading this post, I hope you will understand how a rainbow is formed. Also, I hope you will have knowledge of where the sky is the most beautiful on Earth.

Rainbows happen when sunlight and rain combine with each other in a specific way. When the Sunlight comes down to earth, the light is white. But when this light hits raindrops at a certain angle when coming down, the different colours that make up the beam separate. This is when we see all of the different colours of a rainbow. There are seven colours in a rainbow- red, orange, yellow, green, blue, purple and violet. So, how do all of these colours appear at once? Rainbows appear in seven colours because the water droplets break sunlight into the seven colours of the spectrum. You get the same result when sunlight passes through a prism. So the water droplets are just acting as prisms. The light turns each raindrop into one colour, depending on the angle it came in, resulting in us seeing one colour coming from each raindrop. All the light coming from different angles makes up the seven colours of a rainbow!
The sky is the most beautiful in Svalbard in Norway. Here you can see the ‘Northern lights’. The Northern lights are a physical phenomenon that occurs when electrically-charged particles from the sun hurtle towards the earth. This light becomes visible when the particles collide with gases in the earth’s atmosphere. This can only be seen from the magnetic poles. The polar light in the northern hemisphere is called aurora borealis - or northern lights - while the polar lights in the southern hemisphere are called aurora australis -the southern lights. Below is a picture of the incredible Northern lights.

 I hope you enjoyed reading my Blog! Bye for now!

Friday 6 February 2015

Why does the Sky change colours???

Have you ever seen a beautiful sunset or sunrise where the sky is a mixture of orange and red colours? The view always takes my breath away. The sky changes colours every day, some of the changes in colour may be more significant than others. But I’ve always wondered how the sky changes to some spectacular colours and what the geography behind it is.

Take a look at this video where a news reporter tells us some facts about why the sky changes colours.

As the reporter said, the sky changes colour due to the size of the wavelengths of light. We see the most incredible colours in the Sky during the sunrise and sunset. Think about it. When the sun is rising or setting, it is positioned at a different angle than at the normal daytime. The angle where the sun sits at means that the longer wavelengths are the ones that we can see with our eyes. When the sun is not pointing directly at a point in the earth, then there are more gas molecules between the sun and us. This means we no longer see the short blue wavelengths but we see the longer wavelengths which are red, orange and yellow colours.

The sunset usually has brighter colours than the sunrise. This is because throughout the daytime, humans and animals are walking around and kicking dust up into the light reflection. This will make the sunset colours more vibrant than the sunrise colours. Also, the sunset would look more spectacular in a big city than in the country side because there is more pollution going up into the air in a city than in the countryside!


I hope you learnt something new after reading this post. Check out my next Blog post where I will be explaining how a rainbow occurs and I will also be pointing out an amazing place in the world where the Sky changes to the most beautiful colours.



Saturday 31 January 2015

Clouds, the Night Sky and Stars

Hello again!

Last week, I was talking to my young cousins about the sky and if hey could ask one question what would it be. One of them asked about the clouds and said ‘why don’t they fall down?’ I was struck by this question and decided to include the answer in my Blog. Clouds are made up of mostly tiny water droplets or ice crystals. These water droplets are very light and small that they can float in the air. Also, the wind in the air prevents the small water droplets from falling. This is why clouds don’t fall, but stay in the sky.

In my previous Blog post I mentioned that I would discuss why the Sky goes dark at night and where the stars fit in to all of this. Well, I’m sure that we all know the answer to why the sky goes dark at night, I’ll explain it anyway. The Earth is on an axis that is rotating all of the time. The Earth rotates away from the sun every day and when it is not facing the sun it goes dark. When it is night time we can see the moon and stars. One question which many people have asked is ‘why can’t the stars make the sky shiny and bright?’ Well, the stars are so far away that the total amount of light produced by these stars isn’t enough to make the night sky bright.

I hope that you learnt something new about the Sky in this post. Check out my next Blog post that is going to be about how and why the Sky changes colours from baby blues to rosy reds.



Tuesday 27 January 2015

Why is the Sky blue???

We see the sky everyday no matter where we are in the world. Yet we take the sky for granted. I’m sure all of us have thought and wondered about the sky. Be it when we were children and were wondering why the sky was blue, or when we saw that beautiful sunset and wondered how the sky could do something so amazing. So in this Blog post I am going to give you some facts on the Geography of the sky and what the sky is made up of.

In Wikipedia the definition of the sky is ‘the region of atmosphere and outer space seen from the earth’. The atmosphere is a layer of gases that not only protect the earth from the suns ultraviolent radiation and help preserve life on earth but also gives the sky its colour. The sky colour is due to the atmosphere and the nature of light waves. The earth’s atmosphere not only contains gases but also contains tiny dust particles and particulates which are mostly too small to be seen by the human eye. The smallest particulates are the same length as the wavelength of blue light. This is why the sky is blue.

I hope you enjoyed reading this Blog post on the Geography of the Sky. Make sure to check out my next Blog post where I will be discussing about the clouds in the sky, why the sky goes dark every night and where the stars fit in to all of this!






Friday 9 January 2015


Hello, I'm Jessica and this is my blog on Geography of the Sky! I will be posting about why the sky changes colours so frequently and the geography behind these changes.