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Space Elevator

(neal.fun)
1773 points kaonwarb | 1 comments | 20 Oct 25 04:42 UTC | HN request time: 0s | source
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dpq ◴[20 Oct 25 09:23 UTC] No.45641775[source]▶
Amazing work! One minor correction:

> As particles from the sun hit the atmosphere, they excite the atoms in the air. These excited atoms start to glow, creating brilliant displays of light called auroras.

The process is a bit more nuanced than that. The modern mainstream understanding is that the growing pressure of the solar wind makes the tail of the magnetosphere "contract" (sort of pushing it inwards from the sides), which leads to reconnection of magnetic field lines. Once the reconnection occurs, the magnetic field lines that remain bound to the geomagnetic dipole accelerate the particles on them towards the Earth => they slam into the atmosphere, exciting the atoms and generating the aurora.

replies(2): >>45642819 #>>45643139 #
1. pfdietz ◴[20 Oct 25 11:45 UTC] No.45642819[source]▶
Right. So the solar wind provides the energy that drives the aurora, but it's more indirect than just "solar wind particles hit the atmosphere". Instead, the solar wind is injecting energy into the magnetic field of the magnetosphere, and when reconnection occurs some of this magnetic energy is dumped into particles in the magnetosphere, some of which can then strike the atmosphere.