HELENA — What a show lately. The aurora has been strong and colorful.
Charged particles from the sun strike Earth's atmosphere and its gasses, energizing the gas particles that ultimately release light energy.
The color of that light depends of the energy released by the specific gas atoms and molecules. Earth's atmosphere mainly contains nitrogen and oxygen, so these are the key players in producing aurora colors.
Vivid lime green is the most common color of the aurora, coming from single oxygen atoms colliding with lower energy electrons released by excited nitrogen molecules.
These gases and thus color occur between 60 and 180 miles above the earth's surface.
Red light at the top of the aurora comes from single atomic oxygen. This usually occurs at heights greater than 180 miles above the surface.
Blue and violet occur at 180 miles or higher as hydrogen and helium gas get energized by the solar particles. These colors are rare because these gases are uncommon in the atmosphere.
If you missed light show, do not fear. The solar maximum is expected next year so there should be more activity and opportunity for future light shows very soon.
