Editing 2233: Aurora Meaning

{{comic
| number    = 2233
| date      = November 25, 2019
| title     = Aurora Meaning
| image     = aurora_meaning.png
| titletext = The astro-ph.SR arXiv servers are simultaneously being overwhelmed by electronic requests and actual electricity.
}}

==Explanation==

The phenomenon of an atmospheric {{w|aurora}} (known as aurora borealis in the northern hemisphere and aurora australis in the southern hemisphere) occurs as a result of charged particles emitted by the sun interacting with the Earth's magnetic field. The magnetic field funnels the charged particles towards the polar regions of the earth. At some point, the flow of particles hits the atmosphere, where the particles interact with the molecules of the gases which make up the atmosphere and add to those molecules' energy. Those molecules subsequently release the added energy in the form of light, which is observed as an aurora.

Where in the atmosphere the aurora occurs is related to the quantity and energy of the particles being emitted by the sun. Under normal circumstances, this occurs in high latitudes relatively close to the poles. In less common circumstances of more intense solar activity such as a {{w|solar flare}} or {{w|coronal mass ejection}} (CME), the charged particles are traveling faster and get diverted less by the Earth's magnetic field, so auroras will occur at lower latitudes. This comic indicates both the rarity with which this would occur and the impact it would have on people.

'''Polar latitudes:''' Normal; auroras typically can be seen in these high latitudes.

'''Subpolar latitudes:''' (e.g., southern Canada/northern US, most of northern Europe, northern half of Asia, and numerous small islands in the southern hemisphere) Happens frequently enough to be unconcerned but uncommon enough to be notable and interesting. About a week before the publication of this comic, on Wednesday, November 20, 2019, [https://www.cnn.com/2019/11/20/us/aurora-borealis-wednesday-trnd-scn/index.html aurora activity was visible] in the northern United States and southern Canada.

'''Subtropical/Tropical latitudes:''' Charged particles of sufficient energy to cause auroras at this latitude are very rare and have happened on only a few occasions in recorded history, and not during the space age. A particularly strong one was the {{w|solar storm of 1859}}, which caused failure of telegraph systems all over Europe and North America and in some cases gave telegraph operators electric shocks. An event of that magnitude today would likely interfere with the functioning of electronic systems in orbit, possibly to the point of disabling them entirely, and would cause widespread damage to our now highly electrified world.

'''Equatorial latitudes:''' Auroras have never been recorded here, so all scientific inquiry into what the effect would be on the Earth in general, and on life itself, is purely theoretical. Were this to actually occur, those theories could be proven or disproven based on actual observations (presuming all observers have not been incapacitated or otherwise occupied by the complete breakdown of all electrical and electronic systems as the charged particles induce electric currents in conducting objects). An event powerful enough to have auroras at equatorial latitudes would be extremely energetic and would probably cause very high levels of damage on Earth.

The title text comments on what would happen if auroras were seen in the equatorial band. [http://arXiv.org arXiv.org] is an electronic database of unreviewed, pre-print research papers. The [https://arxiv.org/list/astro-ph.SR/recent astro-ph.SR] sublist is a list of papers in the "Solar and Stellar Astrophysics" topic. So if auroras were seen in the middlemost band, there would be many requests to upload electronic publications on the subject, as well as actual electrical interference to the servers of the website. Randall probably may have been consulting this server for research on the comic, prompting this specific observation.

==Transcript==
:[A drawing of a circle with six dashed lines dividing it into 7 segments with different width. Those at equal distance above and below the broadest middle segments have the same width. Each segment has a label. Above the circle there is a caption:]
:What it means if you see an aurora, by latitude.

:[The labels of the seven segments:]
:Normal
:Cool and exciting
:Someone should go check on our satellites
:A bunch of open questions in solar-terrestrial physics are about to be answered
:Someone should go check on our satellites
:Cool and exciting
:Normal

{{comic discussion}}

[[Category:Astronomy]]