xkcd #3318: Earth Sized Planets

Title text:

It probably has an icy mantle over the real silicate geology, but I'm hoping something weird happened to burn off most of the water like with Io.

Transcript:

Transcript will show once it’s been added to explainxkcd.com

Source: https://xkcd.com/3318/

explainxkcd for #3318

It probably has an icy mantle over the real silicate geology, but I'm hoping something weird happened to burn off most of the water like with Io.

all 7 comments

sorted by: hot top controversial new old
[–] 10 points 1 week ago (4 children)

It's really weird that Venus doesn't have them, but are we sure about Europa?

  • source
  • hideshow 4 child comments
  • [–] 5 points 1 week ago (3 children)

    Isn't that because it doesn't have a large moon constantly kneading the planet with tidal forces?

  • source
  • parent
  • hideshow 3 child comments
  • [–] 6 points 6 days ago (2 children)

    That's my understanding. The moon is probably why we have plate tectonics, and plate tectonics is probably why our surface contains all the elements for life.

    So in other words, a relatively massive moon orbiting relatively close may be the secret to why there's life on earth. (Also, the planet needs to be not tidally locked to that moon)

  • source
  • parent
  • hideshow 2 child comments
  • [–] 1 point 6 days ago (1 child)

    There's a earth sized object on the outer solar system?

  • source
  • hideshow 1 child comment