298790
Encke and the Taurids are believed to be remnants of a much larger comet , which has disintegrated over the past 20,000 to 30,000 years , breaking into several pieces and releasing material by normal cometary activity or perhaps occasionally by close encounters with the tidal force of Earth or other planets ( Whipple , 1940 ; Klačka , 1999 ) .
 person: Whipple
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Whipple 
Answer:
 person: Whipple