A coil-shaped Helix Nebula showing a fine web of filamentary “bicycle-spoke” features embedded in the colorful red and blue ring of gas. At 650 light-years away, the Helix is one of the nearest planetary nebulae to Earth. A planetary nebula is the glowing gas around a dying, Sun-like star. (Photo by Reuters/NASA)

This series of pictures shot by satellite, show the man-made world as astronauts see it. Artist Benjamin Grant uses Google Earth to find the most compelling satellite images of human civilization. The stunning pictures of sprawling metropolises and vast reservoirs are sometimes unidentifiable until zoomed in. In order to find an extraordinary picture in the practically endless supply of satellite data, Benjamin focuses on the themes of current events or environmental issues. Here: Industrial Sector, Tokai, Japan. (Photo by Benjamin Grant/Digital Globe/Caters News)

The X-47B prototype on Tuesday flew off an aircraft carrier and into the history books. Today's achievement, the first-ever catapult launch of an unmanned aircraft from the flight deck of a carrier, promises to open up a new chapter in the annals of naval aviation. Photo: An X-47B pilot-less drone combat aircraft is launched for the first time off an aircraft carrier, the USS George H. W. Bush, in the Atlantic Ocean off the coast of Virginia, May 14, 2013. The U.S. Navy made aviation history on Tuesday by catapulting an unmanned jet off an aircraft carrier for the first time, testing a long-range, stealthy, bat-winged plane that represents a jump forward in drone technology. (Photo by Jason Reed/Reuters)

A participant jumps on vintage skis during a traditional historical ski race in the northern Bohemian town of Smrzovka, Czech Republic, February 20, 2016. (Photo by David W. Cerny/Reuters)

The Historic Photographer of the Year awards celebrate historic places and cultural sites across the globe, from national treasures to hidden gems. Entries were judged on originality, composition and technical proficiency as well as the story that inspired the submission and its historical impact. Here: Overall winner. Mont Saint-Michel by Daniel Burton. (Photo by Daniel Burton/The Guardian)

Shortlisted: Sólheimasandur aircraft crash site, Iceland by Ollie Conway. (Photo by Ollie Conway/Historic Photographer of the Year Awards 2019/The Guardian)

The tempestuous stellar nursery called the Carina Nebula, located 7,500 light-years away from Earth in the southern constellation Carina. (Photo by Reuters/NASA)

Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)