I am going to Iceland. I will leave Nashville on December 4 and return December 9. I will fly U.S. Airways and Iceland Air. There is too much daylight to see the northern lights during the summer because of Iceland's northerly latitude. I will fly into Keflavik Airport. It is 45 minutes to Reykjavik, Iceland's capital. The northern lights are caused by the solar wind hitting gases in the upper atmosphere. Each gas gives off a different color. Green is the most common color.