Simplify the following text for a Grade 8 native English-speaking person.
Original: Sagan was among the first to hypothesize that Saturn 's moon Titan might possess oceans of liquid compounds on its surface and that Jupiter 's moon Europa might possess subsurface oceans of water . This would make Europa potentially habitable for life .
Simplified: Sagan was among the first to guess that Titan and Jupiter 's moon Europa might have oceans or lakes , which means that life could be there .