Nieves penitentes and Earth’s shadow

View larger. | European Southern Observatory Photo Ambassador Babak Tafreshi captured this image in 2014. These ice formations are called nieves penitentes, captured here at the southern end of the Chajnantor plain in northern Chile. Penitentes are found at high altitudes. They form when windblown snowbanks build up and melt due to a combination of high solar radiation, low humidity, and dry winds. The snow melts into the pinnacle shape which earned penitentes their name: they’re said to resemble monks in white robes paying penance. By the way, the dark band near the horizon is Earth’s shadow. Read about living algae recently discovered on penitentes. Image via Babak Tafreshi/ESO.