Imagine a deserted ice desert. The ice surface tops a kilometre-thick ice cap, but in some places there are fissures through the ice, deep cracks from which geysers shoot hundreds of kilometres high into space. The thin atmosphere isn’t enough to support life, and nowhere on the surface is there evidence of plant or tree, lake or ocean – nothing we recognise from life on Earth.
Such is the hostile environment on the moon Europa, which orbits the Solar System’s biggest planet, Jupiter. But if it’s so hostile, why do so many astronomers consider Europa to be our best bet for finding life beyond our own planet?
“Europa is very interesting to study because the oceans beneath the ice caps include
