I'm looking for the name of a sci-fi book based on a generational spacecraft that sent heavy rain (radioactive isotopes) to Earth because they were angry, then later sent a message to Earth warning them about heavy rain and also apologizing.
1 Answer
This is likely Starburst by Frederic Pohl.
The particles are kaons radiation which causes all nuclear material on Earth into a heat meltdown.
If so then it's been asked in here a few times