[PapaBear3625]

Wrong. Neutrons can and do decompose into protons and electrons (beta decay), so the reverse process is certainly not impossible.

It's called electron capture (where the nucleus captures an inner electron and a proton becomes a neutron) and it does occur in nature as a recognized isotope decay mode. See link. Beryllium-7 decays into Lithium-7 via electron capture.

[Wonder Warthog]

"It's called electron capture (where the nucleus captures an inner electron and a proton becomes a neutron) and it does occur in nature as a recognized isotope decay mode. See link. Beryllium-7 decays into Lithium-7 via electron capture."

Thanks for the info. I actually "did" know that, but was having trouble dredging the name up out of deep storage (pre-coffee syndrome, y'know). The last time I had to think about this stuff was forty years ago......

[PapaBear3625]

In a peer-reviewed article in Physical Review Letters: Strong Flux of Low-Energy Neutrons Produced by Thunderstorms:

Received 13 July 2011; published 19 March 2012

We report here for the first time about the registration of an extraordinary high flux of low-energy neutrons generated during thunderstorms. The measured neutron count rate enhancements are directly connected with thunderstorm discharges. The low-energy neutron flux value obtained in our work is a challenge for the photonuclear channel of neutron generation in thunderstorm: the estimated value of the needed high-energy γ-ray flux is about 3 orders of magnitude higher than that one observed.

© 2012 American Physical Society

So lightning seems to be creating low-energy neutrons, by some unknown mechanism. My speculation is that perhaps intense electric fields may cause electron capture somehow.