A haven for extraterrestrial life in another neighboring planet?

Frond-like tracery of cracks on Europa's icy surface (NASA)
Nearly two and a half decades ago, on October 18, 1989, yours truly was stationed at Cape Kennedy, watching as the Atlantis shuttle roaried into the air, ruffling my shirt with the acoustic waves from its giant booster rockets. I was there because Atlantis was carrying a precious cargo, NASA's Galileo mission to Jupiter and her moons, and my lab had nominated me to help staff a small team of Department of Energy information officers a...