Comments by "SeanBZA" (@SeanBZA) on "Today I Found Out" channel.

  1. 99.999998%, as the remaining 0.000002% is cometary ice that hits the atmosphere, or is water made by the recombination of protons from the solar wind with oxygen in the upper atmosphere. Even that oxygen might once have been combined with another 2 protons previously, and have been part of a 21 second stream.
    1