Penitentes are ice spikes of high altitude regions.
Ice melts into vapour . Forming small uneven surfaces . This uneven surface directs sun into dips and away from the peeks continuing the trend
The name comes from the resemblance of a field of penitentes to a crowd of kneeling people doing penance.
In the picture is the field of penitentes in central Andes Argentina
Penitentes were first described in scientific literature by Charles Darwin in 1839.
The effect of penitentes on the energy balance of the snow surface, and therefore their effect on snow melt and water resources has also been studied.