In this July 11, 2016 photo, a young, masked drug trafficker poses for photos holding his guns at a slum in Rio de Janeiro, Brazil. Teenagers openly tote guns while they work as guards, lookouts and distributors for drug lords operating just a few miles from where hundreds of thousands and tourists and athletes will be for the Aug. 5-21 Olympic Games. (Photo by Felipe Dana/AP Photo)

A woman films with her phone the incineration of packages of cocaine, part of a high seas drug seizure of 135 bundles by Salvadoran Naval Force, at a police base in Ilopango, El Salvador, November 29, 2021. (Photo by Jessica Orellana/Reuters)

NASA says it could be another 20 years before humans touch down on Mars, but in a sense, the Mars Society has been exploring the red planet for more than a decade – in Utah. Photo: Csilla Orgel, a geologist of Crew 125 EuroMoonMars B mission, makes her way back to the Mars Desert Research Station (MDRS) in the Utah desert March 3, 2013. The MDRS aims to investigate the feasibility of a human exploration of Mars and uses the Utah desert's Mars-like terrain to simulate working conditions on the red planet. Scientists, students and enthusiasts work together developing field tactics and studying the terrain. All outdoor exploration is done wearing simulated spacesuits and carrying air supply packs and crews live together in a small communication base with limited amounts of electricity, food, oxygen and water. Everything needed to survive must be produced, fixed and replaced on site. (Photo by Jim Urquhart/Reuters)

NASA's Cassini spacecraft has provided scientists the first close-up, visible-light views of a behemoth hurricane swirling around Saturn's north pole. In high-resolution pictures and video, scientists see the hurricane's eye is about 1,250 miles (2,000 kilometers) wide, 20 times larger than the average hurricane eye on Earth. Thin, bright clouds at the outer edge of the hurricane are traveling 330 mph(150 meters per second). The hurricane swirls inside a large, mysterious, six-sided weather pattern known as the hexagon. Photo: The spinning vortex of Saturn's north polar storm resembles a deep red rose of giant proportions surrounded by green foliage in this false-color image from NASA's Cassini spacecraft. (Photo by NASA/JPL-Caltech/SSI)

A general view of the Vintage and Rare Guitars shop on Denmark Street on April 20, 2011 in London, England. Denmark Street, in the Soho area of central London, traces its musical connections back to the 1890s and is famous for its connection to contemporary British music after recording studios started setting up there in the 1960s. Many world-renowned recording artists, including: Jimi Hendrix, The s*x Pistols and Elton John have played and recorded in the street. The Rolling Stones recorded their first album in 1964 at the street's Regent Sounds Studio's. Known as London's 'Tin Pan Alley' Denmark Street is regarded as one of, if not the, best music streets in Europe and contains numerous specialist music shops, with many boasting of a long and prestigious musical history.

“eLEGS is a wearable, artificially intelligent, bionic device that enables people with paralysis to stand up and walk again. The exoskeleton is battery-powered and rechargeable, fitting comfortably and securely over clothing. Initially, eLEGS will be used under medical supervision for rehabilitation and training”. – BerkeleyBionics.com

Photo: Paralysis victim Stephanie Sablan (L) is helped by physical therapist Shonna Moran as she walks using eLEGS robotic legs at Santa Clara Valley Medical Center on May 25, 2011 in San Jose, California. Sablan, 24, was paralyzed from the waist down earlier this year when she was in a car accident and has begun using the newly developed eLEGS made by Berkeley Bionics. The robot-like battery powered eLEGS fit over clothing and enables people with paralysis to stand up and walk again. (Photo by Justin Sullivan/Getty Images)

A woman strikes a police truck with her hand during a protest march in Santiago, Chile, Thursday, April 16, 2015. Thousands of students marched through the streets of Chile's capital to protest recent corruption scandals and to complain about delays in a promised education overhaul. While it was largely peaceful, violence broke out at the end when hooded protesters threw rocks and gasoline bombs at police. (Photo by Luis Hidalgo/AP Photo)

“Freedom”. After the 30 years banning import large motorcycle, in 2007, the Taiwan government reopened the import licensing of the motorcycle displacement over 550 cubic centimeter. Those large bikes, which were never seen before, were strange thought and treated unequally frequently. However, those adversity will not stop those enthusiastic bike riders from chasing the road of freedom. Photo location: Taiwan. (Photo and caption by 火花 羅/National Geographic Photo Contest)