Boat crew members train on the waters of the Tonle Sap River on the morning of the first day of the Water Festival on November 13, 2016 in Phnom Penh, Cambodia. The yearly three-day Water Festival is one of the most important holidays in Cambodia and celebrates the end of the rainy season and the start of the rice harvesting. The Festival also coincides with the Tonle Sap river reversing course, which it does twice a year. Approximately 2 million people are expected to attend this year's festival, during which 259 boats and nearly 20,000 oarsmen will participate in the races. After a fatal stampede resulting in the death of some 353 people during the Water Festival in 2010, it has been cancelled four times over the past five years, with weather used as an official excuse. (Photo by Omar Havana/Getty Images)

28 year old Rupa has her hair shaven to donate to the Gods at the Thiruthani Murugan Temple November 10, 2016 in Thiruttani, India. Rupa donated her hair with the wish that her daughter's illness is cured. The process of shaving ones hair and donating it to the Gods is known as tonsuring. It is common for Hindu believers to tonsure their hair at a temple as a young child, and also to celebrate a wish coming true, such as the birth of a baby or the curing of an illness. The “temple hair”, as it's known, is then auctioned off to a processing plant and then sold as pricey wigs and weaves in the US, Europe and Africa. (Photo by Allison Joyce/Getty Images)

The NASA Extreme Environment Mission Operations (NEEMO) 21 mission began on July 21 as an international crew of aquanauts splashed down to the undersea Aquarius Reef Base, located 62 feet below the surface of the Atlantic Ocean in the Florida Keys National Marine Sanctuary. The NEEMO 21 crew will perform research both inside and outside the habitat during a 16-day simulated space mission. During simulated spacewalks carried out underwater, they will evaluate tools and mission operation techniques that could be used in future space missions, including journeys to Mars. (Photo by Karl Shreeves/NASA)

Palestinian barber Ramadan Odwan styles and straightens the hair of a customer with fire at his salon in Rafah, in the southern Gaza Strip February 2, 2017. In Ramadan Odwan's barbershop in Gaza, hair isn't just blow-dried, it's blowtorch-dried. “People have gone crazy about it, many people are curious to go through the experience and they are not afraid”, he told Reuters. “People here love adventures”. (Photo by Ibraheem Abu Mustafa/Reuters)

The face of a graduating student is displayed on a tablet attached to a robot during a “cyber graduation” ceremony at a school on May 22, 2020 in Taguig, Metro Manila, Philippines. Robots represented some 179 graduating students of the Senator Rene Cayetano Science and Technology High School during a graduation ceremony that was streamed online, as mass gatherings remain prohibited in the country under the Philippine government's lockdown to curb the spread of the coronavirus. The robots were developed by alumni of the school's robotics club, which used tablets to display the faces of the graduating students as they “marched” on stage to receive their diplomas. The Philippines' Department of Health has so far reported 13,434 cases of the coronavirus in the country, with at least 846 recorded fatalities. (Photo by Ezra Acayan/Getty Images)

An artist's impression of a growing supermassive black hole located in the early Universe is seen in this NASA handout illustration released on June 15, 2011. Using the deepest X-ray image ever taken, astronomers found the first direct evidence that massive black holes were common in the early universe. This discovery from NASA's Chandra X-Ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies. (Photo by Reuters/NASA/Chandra X-Ray Observatory/A.Hobart)

Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

A soldier fires a rocket gun as Ukrainian soldiers in the Donetsk region, where the country's most intense clashes occur, attend intensive combat training by using both domestic and foreign weapons amid Russia-Ukraine war in Donetsk, Ukraine on May 08, 2023. Infantry is always prepared in a conflict where heavy weaponry like aircraft, helicopters, tanks and other heavy armored vehicles, artillery systems, and mortars are widely deployed on frontline. Combat readiness and experience training of the 57th Brigade of the Ukrainian army continues in Donetsk. (Photo by Muhammed Enes Yildirim/Anadolu Agency via Getty Images)