“NASA's Pathfinder, Pathfinder Plus, Centurion and Helios Prototype were an evolutionary series of solar- and fuel-cell-system-powered unmanned aerial vehicles. AeroVironment, Inc. developed the vehicles under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. They were built to develop the technologies that would allow long-term, high-altitude aircraft to serve as “atmospheric satellites”, to perform atmospheric research tasks as well as serve as communications platforms”. – Wikipedia

Photo: The solar-electric Helios Prototype flying wing is flies over the Hawaiian islands of Niihau and Lehua during the first solar-powered test flight July 14, 2001 from the U.S. Navy's Pacific Missile Range Facility on Kauai, HI. The 18-hour flight was a functional checkout of the aircraft's systems and performance in preparation for an attempt to reach sustained flight at 100,000 feet altitude later in the summer. (Photo Courtesy of NASA/Getty Images)

“Echus Chasma is a chasma in the Lunae Planum high plateau north of the Valles Marineris canyon system of Mars. Clay has been found in Echus Chasma that means that water once sat there for a time. Echus Chasma is approximately 100 km long and 10 km wide, with valleys ranging in depth from around 1 km to 4 km”. – Wikipedia

Photo: In this handout image supplied by the European Space Agency (ESA) on July 16, 2008, The Echus Chasma, one of the largest water source regions on Mars, is pictured from ESA's Mars Express. The data was acquired on September 25, 2005. The dark material shows a network of light-coloured, incised valleys that look similar to drainage networks known on Earth. It is still debated whether the valleys originate from precipitation, groundwater springs or liquid or magma flows on the surface. (Photo by ESA via Getty Images)

“NASA's Mars rover Opportunity just celebrated its ninth anniversary on Mars – a mission that was originally meant to last just 90 days...” – The Atlantic. Photo: NASA's rover Opportunity visits Victoria Crater, viewed from orbit by the High Resolution Imaging Science Experiment on NASA's Mars Reconnaissance Orbiter in october of 2006. Opportunity is a small dot on the crater's lip, at top right. Opportunity first reached the crater's rim on September 27, 2006. (Photo by NASA/JPL-Caltech/University of Arizona via The Atlantic)

In this January 8, 2015 photo, a monk Kenmyo Muta bows at the condominium construction site and the gate of Sengakuji temple in Tokyo. The “47 ronin” samurai who inspired the long-loved saga of loyalty and honor eulogized in films, books and plays are fighting a new kind of battle in urban Japan. An apartment complex is going up next to the curved tile-roofed Sengakuji temple where the three-century-old graves of the ronin, or masterless samurai, lie. The banner reads: “We only hope to protect landscape of Sengakuji temple”. (Photo by Eugene Hoshiko/AP Photo)

Devotees offer prayers before taking a holy bath during the Swasthani Bratakatha festival in the Triveni River in Panauti near Kathmandu January 24, 2015. During the month long festival, devotees recite one chapter of a Hindu tale daily from the 31-chapter sacred Swasthani Brata Katha book that is dedicated to the God Madhavnarayan and the Goddess Swasthani, alongside various other gods and goddess and the miraculous feats performed by them. The devotees also go on pilgrimages to various temples, perform religious rituals, take a holy bath in the rivers and fast for a month, especially among women who believe fasting helps in their family's well-being or in getting them a good husband. (Photo by Navesh Chitrakar/Reuters)

Ivar Rodningem is a professional illustrator, whose imaginative mind transports us into a parallel world where trolls roam the lands. These creatures might seem scary at first sight, but in reality they are very docile and friendly, help each other and humans that they happen to meet. One of their characteristic features is of course their large noses and long tails. They are one with the nature, which is why it is almost impossible to see a troll if he doesn’t want to be found. Just like you and I they love having fun, though it is hard thing to do, considering their size.

Park Ji-soo of South Korea performs her contemporary variation during the final of the 43rd Prix de Lausanne at the Beaulieu Theatre in Lausanne February 7, 2015. The Prix de Lausanne is an annual international dance competition for dancers aged 15 to 18. A total of 67 participants from 18 countries were selected from 300 applicants to take part in this year's week-long competition, from which the jury has shortlisted 20 finalists to compete for Saturday's finals. Six of this year's finalists will be awarded a one-year all expenses paid scholarship at one of the Prix de Lausanne's partner schools or companies, among the most prestigious in the world. (Photo by Denis Balibouse/Reuters)

A woman lays in a puddle of tomato juice during the annual “Tomatina” tomato fight fiesta in the village of Bunol, 50 kilometers outside Valencia, Spain, Wednesday, August 27, 2014. The streets of an eastern Spanish town are awash with red pulp as thousands of people pelt each other with tomatoes in the annual “Tomatina” battle that has become a major tourist attraction. At the annual fiesta in Bunol on Wednesday, trucks dumped 125 tons of ripe tomatoes for some 22,000 participants, many from abroad to throw during the hour-long morning festivities. (Photo by Alberto Saiz/AP Photo)