ROCCA CALASCIO, Italy, March 22 (Reuters) - When the sun comes up over the castle of Rocca Calascio, a mountain hamlet high up in the central Italian Apennines, it is like a silent, red thunder.

The cold moon sets behind Rocca Calascio castle and village in Calascio, in Italy's Abruzzo region, on December 27, 2023. Sign up for CNN’s Wonder Theory science newsletter.