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)

A photographer has shot this series of scenic selfies – scaling freezing mountain tops to snap himself in front of stunning scenery. Paul Zizkas breath-taking work features himself in front of beautiful backdrops such as shimmering lakes, snowy mountains and vibrant auroras. He has travelled to a number of different locations worldwide including Canada, New Zealand, Niue the South Pacific and French Polynesia. Explorer Paul, from Banff, Alberta, Canada, saw his selfies go viral early in 2014 – and has now unveiled his latest work. He said: I find that sometimes including a person in a landscape scene adds to the photograph – that it conveys a different story. Here: lake Minnewanka, Banff National Park, Alberta, Canada. (Photo by Paul Zizkas/Caters News)

Hawaii has long been known as a tropical paradise, but in recent years another image has intruded into the state's carefully crafted one of idyllic beaches and relaxing resorts: homelessness. The number of homeless people has grown in recent years, leaving the state with 487 homeless per 100,000 people, the nation's highest rate per capita, above New York and Nevada, according to federal statistics. Many of the homeless, however, defy the stereotype of the mentally ill or drug addicted. They are families, with men and women who work full-time jobs. They are struggling to get a foothold in a place with a high cost of living and low wages. Here: in this Thursday, August 27, 2015 photo, a homeless man drinks water while sitting on the beach at Ala Moana Beach Park located near Waikiki in Honolulu. (Photo by Jae C. Hong/AP Photo)

Images of an American ghost town that was home to gold mines and features a plane which crashed during the filming of 3000 Miles to Graceland starring Kevin Costner and Kurt Russell reveal the remnants of the once thriving location. An assortment of rusted vehicles which include a canary yellow bus, caravans and cars have all been left behind in the desert. (Photo by Abandoned Southeast/Mediadrumworld.com)

People struggle with the wind as they cross the street under the rain as typhoon Mitag is expected to hit northern Taiwan, in Keelung, Taiwan, 30 September 2019. According to report, Typhoon Mitag will disrupt air, land and water traffic. Mitag is located at sea about 290 kilometers off the south-southeast of Yilan County, moving at 27 kilometers per hour at a northwesterly direction, with maximum sustained winds of 126 kilometers per hour, with gusts of up to 162 kilometers per hour, and with a radius of 180 kilometers, according to Taiwan Central Weather Bureau. (Photo by Ritchie B. Tongo/EPA/EFE/Rex Features/Shutterstock)

People enjoy the fine weather on the coast at Wembury during the first ever nationwide survey to map the location of the threatened and creatures on March 24, 2011 in near Plymouth, England. Often found on the coast, and particularly in the south west of England, the number of oil beetle species found in the UK has halved in the last 100 years and the survey will help establish the whereabouts of the remaining four species and boost efforts to secure their future. The survey is being launched today by Buglife: The Invertebrate Trust and the National Trust in partnership with Natural England and Oxford University Museum of Natural History. (Photo by Matt Cardy/Getty Images)

A young boy rests by empty USAID vegetable oil tins in the Dagahaley refugee camp which makes up part of the giant Dadaab refugee settlement on July 19, 2011 in Dadaab, Kenya. The refugee camp at Dadaab, located close to the Kenyan border with Somalia, was originally designed in the early 1990s to accommodate 90,000 people but the UN estimates over 4 times as many reside there. The ongoing civil war in Somalia and the worst drought to affect the Horn of Africa in six decades has resulted in an estimated 12 million people whose lives are threatened. (Photo by Oli Scarff/Getty Images)

“Mount Hua, or Hua Shan, or Xiyue located near the city of Huayin in Shaanxi province, about 120 kilometres (75 mi) east of Xi'an. It is one of China's Five Great Mountains, and has a long history of religious significance. Originally classified as having three peaks, in modern times the mountain is classified as five main peaks, of which the highest is the South Peak at 2,154.9 metres (7,070 ft)”. – Wikipedia

Photo: Trip to Xi'an 西安. (Photo by Grant Robinson)