Mary McHugh mourns her slain fiance Sgt. James Regan at “Section 60” of the Arlington National Cemetery May 27, 2007. Regan, a US Army Ranger, was killed by an IED explosion in Iraq. (Photo by John Moore/Getty Images)

Villagers walk over a tree felled by rain in the village of Punta Caimanes, a place affected by heavy rains in the Izabal region, near Guatemala City, August 8, 2015. Heavy rains have affected eight communities in the municipality of El Estor and five in Livingston, both located in the region of Izabal, with five deaths due to floods, according to local media. (Photo by Josue Decavele/Reuters)

Animal rights activists, including musician Kris Reichert, center, hold up signs with writing in Italian reading; “Leather: a lethal look” and “I wouldn't wear animal skin even if I were dead” as they stage a demonstration in front of Milan's Duomo gothic cathedral, Italy, Wednesday, September 20, 2017. Milan Fashion Week previews kick off Wednesday with Gucci, leading up to the awards on Sunday night. (Photo by Luca Bruno/AP Photo)

Two Bulgarian tourists pose in front of the Eiffel Tower in Paris on their last day in the capital on March 24, 2014. (Photo by Franck Fife/AFP Photo)

Shortlisted. Dragonfly, North York Moors national park, by Jonathan Green: “In June I was at May Beck with some colleagues when someone spotted this Hawker perched in a gorse bush. I love the detail on the wings, and it’s rare to be able to get so much of such a small subject in clear focus. Getting a few scratches was worth it”. (Photo by Jonathan Green/2020 UK National Parks Photography Competition)

People look at a tanker after it fell into a caved-in area on a road in Xi'an, Shaanxi province, July 27, 2013. No casualty was reported in the accident, according to local media. (Photo by Reuters/Stringer)

A general view shows smoke and volcanic ashes billowing from volcano Cotopaxi in Pedregal, Ecuador, late 07 October 2015. (Photo by Jose Jacome/EPA)

Penitentes, or nieves penitentes (Spanish for “penitent-shaped snows”), are a snow formation found at high altitudes. They take the form of tall thin blades of hardened snow or ice, closely spaced with the blades oriented towards the general direction of the sun.