This postcard of an aurora borealis comes from Tuula from Finland. The Northern Lights or aurora borealis is caused as a result of charged particles from the sun that collide with atoms and molecules in the earth’s atmosphere at an altitude of between 90 and 250 kilometers. It is due to this collision that oxygen and nitrogen emit the light that we perceive. On the other side of the planet, a similar event takes place, the lesser known, Southern Lights or aurora australis can be viewed from the Southern parts of Australia, New Zealand, South America and also in Antarctica. Unfortunately for me, South Africa just is not south enough. Aurorae also occur on other planets in the solar system, specifically at the magnetic north pole of the planet. Very interesting to know about this, thank you Tuula!
From Marja-Liisa in Finland, I got this postcard. I really do like the aurora borealis on it. In fact, I would like more of these kinds of postcards from Finland. She tells me that the minimum temperature there on the day she sent the postcard was -4 degrees celsius. Let’s just say that I have never felt that kind of temperature and I really wouldn’t like to! So, anyway, thank you Marja-Liisa, I like the postcard!