Free Republic
Browse · Search
General/Chat
Topics · Post Article

To: metmom

Northern lights (aurora borealis) — What they are and how to ...The aurora borealis, or northern lights, is a natural light display in the Earth’s northern hemisphere caused by solar particles colliding with gases in the upper atmosphere. We saw that here in central KS last night. First time in my life. Spectacular.


9 posted on 11/12/2025 10:45:25 AM PST by kawhill ("And we'll do what we must, and we'll cry without making a sound". Corbin, John)
[ Post Reply | Private Reply | To 1 | View Replies ]


To: kawhill

Here is a fact that most people don’t know about the Northern Lights. The colours you see indicates the elements that are hitting earth’s atmosphere.

The green color in the northern lights (aurora borealis) is primarily produced by **oxygen** atoms.

### How It Works
- When charged particles from the Sun (solar wind) collide with Earth’s upper atmosphere (about 100–300 km altitude), they excite oxygen atoms.
- These excited oxygen atoms then release energy as light when returning to their ground state.
- **Green light** (wavelength ~557.7 nm) is the most common emission from oxygen at these altitudes.

### Other Colors for Context
- **Red**: Higher-altitude oxygen (>300 km).
- **Blue/purple**: Nitrogen molecules.
- **Pink/red edges**: Nitrogen at lower altitudes.

The iconic emerald green dominates because oxygen is abundant and the 557.7 nm emission is strong under typical auroral conditions.


15 posted on 11/12/2025 10:51:03 AM PST by Jonty30 (I've been diagnosed as being polemic and there is no cure. )
[ Post Reply | Private Reply | To 9 | View Replies ]

To: kawhill

A roaring, boring Alice, you say? I know her.


29 posted on 11/12/2025 11:30:49 AM PST by Dr. Zzyzx
[ Post Reply | Private Reply | To 9 | View Replies ]

Free Republic
Browse · Search
General/Chat
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson