Europa and Enceladus: Probing Subsurface Oceans on Ice-Covered Worlds

To the point

Researchers Kris Zacny and Emily Klonicki describe international efforts, including NASA's Europa Clipper and the JUICE mission, to explore Europa's and Enceladus's hidden oceans by drilling through thick ice or sampling icy plumes with melt probes and robot submarines, despite major technical and budget hurdles, in the quest to find biosignatures and prove life-friendly environments beyond Earth.

Alien-life hunters are eyeing icy ocean moons Europa and Enceladus
space.com

Alien-life hunters are eyeing icy ocean moons Europa and Enceladus

The late 2030s are a realistic launch target for an alien-ocean explorer, should NASA choose to develop one.