Lighting up the night sky with greens and reds, these are the spectacular aurora by a photographer in the world’s northern regions.
These amazing pictures of the northern lights were taken by astrophotographer Juan Carlos Casado in Greenland, Iceland and Finland.
He said: “Auroras are one of the most spectacular natural phenomena that can be seen.
“They are global spectacles, in the sense that they can cover the whole visible sky and combine with the terrestrial landscape as a wonderful symphony.
“My images try to capture these unique and unrepeatable moments: the shapes, colours and movements of auroras are never repeated.
“I have travelled several times to Iceland and south Greenland, where I have captured these images,
The particles originate from the Sun and reach the Earth in a stream of solar wind.
The solar wind is made up of many charged particles, elements, and isotopes that are present in the Sun.
These are ejected in events that are called coronal mass ejections - eruptions from inside the sun and appear as sunspots.
As this wind reaches the Earth, it is deflected by our magnetosphere, an invisible shield created by the Earth’s magnetic field, which protects us from such particles.
But at the North and South poles, the field lines go towards the Earth, like a funnel.
The green comes from oxygen molecules but purple is usually a mixture of red and blue emissions from molecular nitrogen.
At various times in the winter the aurora can be viewed in Scotland.
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