PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • Clouds, not due to dust, have even been seen in the Martian sky and there is a global water cycle in which nightly frosts of water ice are deposited on boulders and other surfaces due to evaporation and condensation reactions driven by the water supplied by Mars' icy poles.
http://www.w3.org/ns/prov#wasQuotedFrom
  • nasa.gov