Students from Langata primary school run past riot police as they protest against a perimeter wall illegally erected by a private developer around their school playground in Kenya's capital Nairobi January 19, 2015. Riot police used teargas to disperse students at a school in Nairobi as the children protested against the potential loss of their playground. The playground was fenced off in December, during the school holidays, by a prominent developer who also claims ownership of the land. The title to the contested site is said to be in the name of Airport View Housing Limited, according to local media, with plans to use the space to build a parking lot for a hotel. (Photo by Thomas Mukoya/Reuters)

“Richard Wilson (born May 24, 1953) is a sculptor, installation artist and musician. Wilson's work is characterised by architectural concerns with volume, illusionary spaces and auditory perception”. – Wikipedia

Photo: An installation by the artist Richard Wilson, entitled “Turning the Place Over”, is built into the condemned Cross Keys House in Moorfields as part of the Capital of Culture for 2008, on June 25, 2007 in Liverpool, England. The piece consists of an 8 metre ovoid cut from the building's facade that oscillates in three dimensions. (Photo by Jim Dyson/Getty Images)

“The Lovell Telescope is a radio telescope at Jodrell Bank Observatory, near Goostrey, Cheshire in the north-west of England. When it was constructed in 1955, the telescope was the largest steerable dish radio telescope in the world at 76.2 m (250 ft) in diameter; it is now the third largest, after the Green Bank telescope in West Virginia, USA, and the Effelsberg telescope in Germany. It was originally known as the 250 ft (76 m) telescope or the Radio Telescope at Jodrell Bank, before becoming the Mark I telescope around 1961 when future telescopes (the Mark II, III, and IV) were being discussed. It was renamed to the Lovell Telescope in 1987 after Bernard Lovell, and became a Grade I listed building in 1988. The telescope forms part of the MERLIN and European VLBI Network arrays of radio telescopes”. – Wikipedia

Photo: The Lovell Telescope listens to the night sky for radio signals from space at Jodrell Bank on June 22, 2011 in Holmes Chapel, England. Jodrell Bank Centre for Astrophysics and it's world famous Lovell Telescope is on the shortlist of Britain's submission for Unesco World Heritage Site status. (Photo by Christopher Furlong/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)

“The Dream Chaser is a planned crewed suborbital and orbital vertical-takeoff, horizontal-landing (VTHL) lifting-body spaceplane being developed by SpaceDev, a wholly owned subsidiary of Sierra Nevada Corporation (SNC). The Dream Chaser design is planned to carry seven people to and from low earth orbit. The vehicle would launch vertically on an Atlas V and land horizontally on conventional runways”. – Wikipedia

Photo: NASA Deputy Administrator Lori Garver talks during a press conference with Sierra Nevada's Dream Chaser spacecraft in the background at the University of Colorado at Boulder on February 5, 2011 in Boulder, Colorado. Sierra Nevada's Dream Chaser spacecraft is under development with support from NASA's Commercial Crew Development Program to provide crew transportation to and from low Earth orbit. NASA is helping private companies develop innovative technologies to ensure that the U.S. remains competitive in future space endeavors. (Photo by Bill Ingalls/NASA via Getty Images)

Employees stand near an airframe for the second Antonov-225 Mriya plane at Antonov aircraft plant in Kiev, Ukraine, September 7, 2016. Ukraine hopes to attract $500 million of investment from China to complete an updated version of the world's biggest aircraft, the Antonov-225 Mriya, the president of manufacturer Antonov said on Wednesday. (Photo by Valentyn Ogirenko/Reuters)

“SpaceShipOne was a suborbital air-launched spaceplane that completed the first manned private spaceflight in 2004. That same year, it won the US$10 million Ansari X Prize and was immediately retired from active service. Its mothership was named “White Knight”. Both craft were developed and flown by Mojave Aerospace Ventures, which was a joint venture between Paul Allen and Scaled Composites, Burt Rutan's aviation company. Allen provided the funding of approximately US$25 million”. – Wikipedia

Photo: A chase plane follows SpaceShipOne after it reached a height of 62 miles in the first non-governmental flight to leave the Earth's atmosphere on June 21, 2004 in Mojave, California. SpaceShipOne spacecraft was carried to a height of 50,000 by the twin-turbojet high-altitude research aircraft, “White Knight”, where it was launched for its final climb. The space effort was funded by Microsoft co-founder Paul Allen and headed by aerospace engineer Burt Rutan. (Photo by Jim Campbell-Pool/Getty Images)

Russian support personnel work to help get Expedition 29 crew members out of the Soyuz TMA-02M spacecraft shortly after the capsule landed with Expedition 29 Commander Mike Fossum, and Flight Engineers Sergei Volkov and Satoshi Furukawa on November 22, 2011 outside of the town of Arkalyk, Kazakhstan. NASA Astronaut Fossum, Russian Cosmonaut Volkov and JAXA (Japan Aerospace Exploration Agency) Astronaut Furukawa are returning from more than five months onboard the International Space Station (ISS) where they served as members of the Expedition 28 and 29 crews. (Photo by Bill Ingalls/NASA via Getty Images)