https://phys.org/news/2018-07-jupiter-moon-europakey-future-missions.html

By studying this material from the interior, scientists developing future missions hope to learn more about the possible habitability of Europa's ocean.However, Europa's surface is bombarded by a constant and intense blast of radiation from Jupiter. This radiation can destroy or alter material transported up to the surface, making it more difficult for scientists to know if it actually represents conditions in Europa's ocean.

As scientists plan for upcoming exploration of Europa, they have grappled with many unknowns: Where is the radiation most intense? How deep do the energetic particles go? How does radiation affect what's on the surface and beneath—including potential chemical signs, or biosignatures, that could imply the presence of life.