Sunday, May 17, 2009

The Signs of Spring



Most people recognize spring by blooming flowers, singing birds, and even warmer nights, but what most people don't realize is that spring is aurora season. The weeks around the vernal equinox are prone to Northern Lights. As shown in the picture, auroras are green curtains of light dancing across the sky, and are caused by solar activity. Scientists still haven't figured out why one season has more auroras than another, because the sun doesn't know what season it is. In order to learn a little more about auroras, NASA has deployed five spacecrafts named THEMIS ("Time History of Events and Macroscale Interactions during Substorms"). Auroras may look like just pretty lights in the sky to average people like us, but they are so much more. Underlying each display is a potent geomagnetic storm with possible side-effects ranging from satellite malfunctions in orbit to power outages on Earth. In a society that relies heavily on space technology, understanding these storms is vital. In the article, "Aurora Borealis and Aurora Australis are Best Observed in Spring" , by Tony Phillips, he explains what they have found so far. THEMIS has already observed a very fast moving storm, 60 seconds flat, and very, very high energy. NASA is using THEMIS to discover the storm power supply. "The satellite has detected magnetic "ropes" connecting Earth's upper atmosphere directly to the sun." "We believe that solar wind particles flow in along these ropes, providing energy for geomagnetic storms and auroras." This magnetic connection between the sun and the Earth are favored in springtime. "Around the time of the equinox, Earth's magnetic field is best oriented for connecting-up with the sun, opening the door for solar wind energy to flow in and spark Northern Lights." Autumn is aurora season also, it is just that the geomagnetic disturbances are almost twice as likely in the spring. THEMIS is on a two year mission, so we are very likely to see a lot of facts from THEMIS that explain the auroras.

The aurora borealis is a great tourist attraction for people in Alaska. Spring generates much needed tourist money. However, they may find that it could be dangerous since these storms have so much magnetic power, information that THEMIS is just gathering. I thought it would be cool to be able to see these storms in our area. We may find out in the next couple of years that it is better to be contained to the northern area. I imagine this would continue to please the merchants. It affects more than just the tourist area; including, NASA, scientist and engineers as well as their staff. These people work all over the country and that helps stimulate the economies of where they live because they are employed and put their money back into their communities. It takes a lot of people to build, maintain and gather information from THEMIS.
It will be an interesting discovery to follow over the next couple of years!
For more information on aurora borealis and this article check out http://geology.com/nasa/aurora-borealis.shtml.

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