Life in Alien Oceans

Today I watched Isaac Arthur's YouTube video about the possibility that oceanic life could develop on other worlds. I almost regret doing watching this video because I was a little happier not knowing sea spiders are a thing that exists on Earth. Also imagining the possibility that some alien spider species evolved on a water world and became space faring...yikes!

On one hand an alien species that evolved in an exoplanet ocean or under a layer of ice on a large moon might never create technology. It's hard to have an Iron Age or Bronze Age under water where fires can't be started. On the other hand there are probably geothermal vents on the ocean floor of other planets like there are on Earth so some alloys might be made that way.

If technology can be developed on large moons by alien creatures that can breathe both air and in water then space colonization might be easier for that species. The escape velocity of a large moon is less than Earth's and methane from the ice could be used as rocket fuel. There might be other nearby moons to establish colonies on.

Great. A whole alien solar system might be dominated by alien sea spiders. One less place space tourists will need to visit.

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Daily Activity, Walking