THE red tinge of Europa, one of Jupiter’s moons, could be caused by frozen
bits of bacteria. Their presence would also help explain Europa’s mysterious
infrared signal.
Europa is mostly frozen water, but it absorbs infrared radiation differently
to how normal ice does. Researchers think this is because something is binding
the water molecules together. Salts of magnesium sulphate frozen within the ice,
for example, would make the molecules vibrate at different frequencies. But no
one has managed to come up with the perfect mix of salts to explain all of
Europa’s spectrum.
Astrogeophysicist Brad Dalton wondered if something else…
