About: http://webisa.webdatacommons.org/200054937

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	Today scientists speculate that the cause was a piece of comet, a 'dirty snowball' of water and gases that exploded and vaporized on entering the earth's atmosphere, and so left no crater.
http://www.w3.org/ns/prov#wasQuotedFrom	historynet.com