How Big Could Life Be on Europa?

I have been fascinated with the prospect for life on Jupiter’s moon Europa since I first heard about it as a child. But I have just one question: what kind of life? When I was a child, I thought they might have meant human-like life. Of course, I now realize that ever primitive bacteria would qualify for life by the people who claim there might be life there (NASA, I believe).

I guess what I am trying to ask is exactly how big could the animals be on Jupiter’s moon (as I’ve said, I now realize human-like life is probably out of the question)? Are we talking about a dinosaur-type life? Or in fact is bacteria basically what is meant by “life” here. If anyone has a link, that would be very helpful.


  1. It would have to live in the ocean under Europa’s icy surface

  2. It’s power source would be hydrothermal vents like those found on Earth or something simlair.

Anything else is just guessing.

Low gravity + water buoyancy may = huge, but don’t quote me on that.


[speculaton] Where are ‘huge’ critters going to obtain enough energy to maintain their bulk.[/speculaton]

I’d like to think Bosda is correct, I hope our bacteria don’t screw it up. I couldn’t find a link, but I loved the pictures of the ‘floaters’ and ‘hunters’ in the atomosphere of Jupiter itself in Sagan’s Cosmos. I wish NASA would get out of the space vacation business and concetrate on robotic planetary exploration.

Well, scientists think there could be a liquid ocean beneath Europa’s icey exterior. If this is true, and if there are enough sources of energy (similar to earth’s thermal vents) we could see a variety of life forms.

Not sure how large we could possibly be talking about, who knows how evolution would wprk in such an environment. If it is anything like earth’s ancient oceans however, then anythign goes.

Most likely it’ll be bacteria or something of the sort (well, most likely, there won’t be anything, but if there is something it’s most likely bacteria). Even on our own planet, multicellular life is something of a fluke. As I recall, prokaryotes (bacteria) were the only thing on the planet for the first billion years or so, without even internal organelles (nucleus, mitochondria, etc.), and even today, there’s a higher biomass in bacteria than in anything else.

But we have no observational evidence at all yet about Europa; the only thing we can say definitively about the size of any lifeforms is that they’re small enough to fit in an ocean.

Well, the entire ocean could be a single organism, with rootlike tendrils extending through the ice, and onto the surface; sort of a Solaris-like planetary beastie. That’d make it slightly larger than the central ocean.