About: http://webisa.webdatacommons.org/50897418

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	The scientists have already produced ground spheres made of steel, other metals such as titanium and various alloys are envisaged for the future.
http://www.w3.org/ns/prov#wasQuotedFrom	phys.org