As we made our way from base camp for an acclimatisation hike on Ojos del Salado in the Puna de Atacama region of the Andes last month, we witnessed a strange phenomenon in the sky.
Read moreWhat the devil is a circumhorizon arc?

As we made our way from base camp for an acclimatisation hike on Ojos del Salado in the Puna de Atacama region of the Andes last month, we witnessed a strange phenomenon in the sky.
Read more