Last time we met, I showed you how you could use a video of an astronaut wringing out a wet towel to talk about surface tension with a young student. Today, we are going to discuss the phenomenon only a few on Earth and even fewer in space get to witness. Auroras, or the Northern and Southern lights, are an incredible sight, one I have only been able to enjoy in pictures and videos. If I was not so ill-equipped to deal with the cold, I would travel to northern Canada or Alaska in the dead of winter just to be able to see the green, red, and purple lights that light up the night sky.
An aurora occurs when a solar wind is so massive that the energy from the sun is drawn into the Earth's magnetic field. When these charged particles, mostly the electrons, interact with the gases in our atmosphere, they give off light. Each specific gas gives off the color we see! Since the Earth has two magnetic poles, north and south, we have both the Northern Lights and the Southern Lights. You may be thinking to yourself how you often only hear about the Northern Lights, or scientifically called the aurora borealis. The reason this is the case is the areas near the North Pole are more populated and therefore there are more sightings. The aurora australis, or Southern Lights, is caused by the same interactions in the universe and can be seen from Antarctica.
In this video, you can listen to two astronauts discussing this phenomenon and comparing the vision from space and from the Earth. It's pretty fabulous to see what it looks like from space!
When you're using this video to talk about the nature's light show with your kids, you may want to give more details. For example, interaction of the electrons with oxygen atoms is what gives off red and green light. The red light comes from oxygen atoms in the upper atmosphere while the green is a result of lower altitude oxygen. Nitrogen atoms colliding with the solar energy causes the blue and violet colors observed in the sky.
While these phenomena occur frequently, we must be at higher altitudes or lower altitudes to observe them. For example, scientists go to Antarctica, despite the pesky temperatures, to study the aurora australis. Many tourists will travel to the upper parts of Canada and Alaska to witness the aurora borealis. The requirements to see one involve a dusk to night sky in the winter and a lot of patience since the timings of their occurrences are largely unpredictable.
For those of us who cannot enjoy them in person, thankfully a few incredible photographers have given us the joy of seeing them through their lens. Here are a few resources you can visit with your child. I hope you enjoyed learning about and discussing this topic, and I look forward to bringing you more science mentoring resources.
Calvin Hall Photography
Lights over Lapland