<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://pop.h-cdn.co/assets/cm/15/05/640x320/54cae9894d366_-_mars-spirals-01-0412-de.jpg>
<http://www.popularmechanics.com/space/moon-mars/a7713/how-lava-created-strange-spirals-on-mars-8392905/>