Solar

A long time exposed picture taken by night shows the Solar observatory at the peak of the Lomnicky Stit, in the Slovakia's High Tatras mountains, on September 04, 2014. The coronal station at Lomnicky Stit observatory, built at 2 632 meters between 1957 and 1962, ranks among five existing stations worldwide which systematically observe emission spectral lines of the corona.

Joe Klamar/AFP

The solar observatory on Lomnicky Stit, in Slovakia’s High Tatras range, on Thursday. The station is one of five worldwide which observe emission spectral lines in the sun’s corona.

The world's largest solar-powered boat, "MS Turanor PlanetSolar" sails through the Corinth Canal near the town of Corinth on July 28, 2014.  The boat arrived to Greece as part of a joint archaeological project focused on underwater exploration off one of Europe's oldest human occupation sites, the Franchthi cave in the Argolid, southeast Peloponnese. The project is taking place in one of Greece's richest archaelogical areas, the Argolid, known for its major palatial complexes in the Bronze Age that include Mycenae and Tiryns and later, classical-era city-states and sites like Argos and the ancient-theatre site of Epidaurus.

Valerie Gache/AFP

The world’s largest solar-powered boat, “MS Turanor PlanetSolar” sails through the Corinth Canal near the town of Corinth on Monday. The boat arrived to Greece as part of a joint archaeological project focused on underwater exploration off one of Europe’s oldest human occupation sites, the Franchthi cave in the Argolid, southeast Peloponnese

Experimental aircraft 'Solar Impulse 2',

Laurent Gilleiron/EPA

The experimental aircraft “Solar Impulse 2″, HB-SIB, during solar generator tests at an air base in Payerne, Switzerland, on Monday. The project aims to achieve the first circumnavigation of the world with an aircraft powered only by solar energy.

Solar Impulse, piloted by AndrÈ Borschberg, takes flight during the second leg of the 2013 Across America mission, at dawn, Wednesday, May 22, 2013, from Sky Harbor International Airport in Phoenix. The solar powered aircraft is scheduled to land at Dallas/Fort Worth International Airport on Thursday May 23. The plane's creators, Bertrand Piccard and Borschberg, said the trip is the first attempt by a solar airplane capable of flying day and night without fuel to fly across America. (AP Photo/Matt York)

Matt York/AP

Solar Impulse, piloted by André Borschberg, takes flight during the second leg of the 2013 Across America mission at dawn on Wednesday from Sky Harbor International Airport in Phoenix, Arizona. 

A man look up at a starry night at Kielder Water, Northumberland.

Tom White/PA

Stargazer delight: a man takes in the beautiful spectacle of the unusually clear night sky over Kielder Water, Northumberland, northeast England, on Tuesday