Aurora FAQ NASA / Terry Zaperach A luminous glow of the upper atmosphere caused by What is the aurora? energetic particles that enter the atmosphere from above. What kind of energetic Electrons and protons. particles? Where do the energetic particles The sun (solar wind). come from? The outermost layer of the What is the solar sun, which is so hot that it boils off as a very thin gas wind? which flows outward like wind. A volume of space What is the surrounding the Earth, magnetosphere? produced by its magnetic field. They follow Earth’s magnetic Where do the field lines into the upper atmosphere, where they energetic particles go? bump into atoms and molecules and excite them. The atoms or molecules jump What does “excite” up to a higher energy state, mean? then give off light as they fall back down to their original state. The kinds of gases in the atmosphere and their height. What causes the Oxygen higher in the atmosphere = red different colors of the Oxygen in the middle of the aurora? atmosphere = green Nitrogen lower in the atmosphere = purple Lowest: 80 km/50 miles. What is the altitude of Highest: 600 km/350 miles (about how high the space the aurora? shuttle flies). Typically the bottom edge is at 100 km (60 miles). Why does the aurora It follows the curved shape of sometimes look like Earth’s magnetic field lines. curtains? It is always happening How often does the somewhere on Earth, but we aurora occur? can’t always see it. We need a dark, clear sky to see it. Yes! It occurs in oval shapes around the north and south Does the aurora occur magnetic poles. In the north, it is in the Southern called the aurora borealis Hemisphere? (northern lights). In the south, it is called the aurora australis (southern lights). Where is the best High northern latitudes in place to see the winter (Alaska, Canada, aurora? What time is Scandinavia). The best time to best? watch is around midnight. .