What is Europa and why are scientists particularly interested in investigating this object?
One of the larger moons of Jupiter and is one of the most likely locations for extraterrestrial life in our solar system.
Scientist have discovered that Europa has an ice-water crust with cracks in it. Europa has a surface temperature well below -100 degrees C. At this temperature ice is as hard as concrete, so the fact that it has cracks is somewhat unusual. The probable reason for these cracks is that far beneath the surface, the core of the moon is warm enough to melt the water. So it is quite likely that it has liquid water which is one of the things necessary for life as we know it.
Additionally, what little atmosphere it has, contains oxygen. This means that through the cracks in the ice the liquid water could be oxygenated. Meaning that perhaps there is life there and perhaps this life is more complicated than anaerobic bacteria.
They did a special on the 4 Galilean moons of Jupiter, on Discovery channel or some similar channel. It is worth searching for and watching.