[dumbfoundded]

It's like you didn't even read the article. There's also an actual cold fusion using muons. Only problem is muons take more energy to create than they help create through fusion. If you had a free muon source (like the sun), you could potentially create a space-based fusion reactor operating at room temperature.

[fsh]

The sun is not a muon source. Muons have a 2 us lifetime, so even highly relativistic ones don't get very far before decaying.

[dumbfoundded]

The sun is absolutely a muon source. Almost every muon that hits Earth's surface is caused by cosmic rays from the upper atmosphere creating pions that decay into muons. (1) The average flux is 1 muon per cm^2 per sec (2). Muons only live a few microseconds but this is plenty of time to catalyze fusion reactions. The two problems with muon-assisted fusion are the energy cost of producing muons with current technology and the potential of muons to stick to alpha particles. Both limit the efficiency of the technique. (3)

(1) https://muonsources.org/science-with-muons/how-are-muons-pro...

(2) https://cosmic.lbl.gov/SKliewer/Cosmic_Rays/Muons.htm#:~:tex....

(3) https://en.wikipedia.org/wiki/Muon-catalyzed_fusion

[fsh]

Sure, the particle showers that cosmic rays create in the atmosphere contain some muons. Still the sun itself does not emit muons, and even if it did they would decay long before reaching earth (or a satellite).