81890
Deep-sea vents were discovered in 1977 by Jack Corliss and Robert Ballard in the submersible .
 Jack Corliss, Robert Ballard
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Jack Corliss, Robert Ballard