What types of predictions are haram and is saying something wont happen haram?

assalamualaikum, I know prediction is a sin but can you explain to me exactly what prediction is yesterday i was in a conversation and i said **“there no way we’ll be able to live on mars”** and i just said it because i found it unbelievable so does it count as predictions and will my salah not be accepted for 40 days? And thank you.