There are videos of the physicist Vogt talking about how the sun goes nova periodically and how that causes the ice ages. He explains how, among other things, comets are formed during these events which happen every 12 thousand years or so. The next due date is 2046, I believe.
https://www.youtube.com/watch?v=bMr-5HHnAmU
https://www.youtube.com/watch?v=PS_yq19Af-s
https://www.youtube.com/watch?v=m-g4Xt-VVzA