For me, Earth Hour is one of the most inspirational events of the year. It’s the world’s largest mass participation event for the environment, bringing together millions of people, businesses and governments to share a common cause and a common sense of purpose – the need to tackle dangerous global climate change.
Last year, people in 162 countries ‘switched off and had fun in the dark’ to support Earth Hour. This simple, symbolic gesture shows that we really do care about the future of our planet.
But there are some lights that you just wouldn’t want to switch off. The Northern Lights (Aurora Borealis) and the Southern Lights (Aurora Australis) are amongst nature’s most spectacular displays, and I’ve been fortunate to witness them in both polar regions.
Early explorers marveled at them. Inuit, Viking and Maori recounted legends about them, including stories of evil spirits, feasts with the gods or kinsmen trapped in polar ice-caps lighting bonfires as rescue beacons.
So what are these lights that arc across the polar skies, dancing and shimmering, twisting and turning and rolling over themselves? This video goes some way to capturing their wonder and beauty.
In fact, the aurora are caused by solar wind from the sun hitting the magnetic field of the Earth above the poles and producing electrical currents. These currents cause atmospheric gases to glow. Or – to put it another way – it’s a bit like having a massive fluorescent tube flickering above each of the poles!
My top 10 illuminating facts about the Aurora
- The Aurora occur in the upper atmosphere and are commonly seen during the night in the polar regions.
- The Aurora Borealis occurs over the Earth’s north geomagnetic pole and the Aurora Australis occurs over the south geomagnetic pole – in regions known as ‘auroral ovals’
- Occasionally the Aurora Borealis can be seen from here in the south of England, but this takes place only once or twice a decade.
- The Aurora Borealis is named after the Roman goddess of the dawn, Aurora, and the Greek term for “wind of the north,” boreas.
- Captain James Cook coined the term Aurora Australis following his voyage of discovery to the Antarctic in his ship the Resolution (1772-1775)
- Green is the most common colour in the Aurora and is caused by atomic oxygen at altitudes of about 100 and 200kms.
- Red is only seen in the Aurora if the atomic oxygen is created above 250 kms
- Aurora also occur on other planets, including Jupiter, Saturn, Uranus and Neptune.
- The Aurora on Saturn is only seen in ultraviolet light and can only be observed from space.
- Astronauts on board the International Space Station are at roughly the same altitude as the auroras so they see them from above or side-on!
Enjoy Earth Hour wherever you are
Let’s make sure that governments across to world also come together to strike a fair deal on tackling climate change.