You already knew the answer to ‘What would happen if you moved at the speed of light’ was was “To actually reach the speed of light you’d be massless.” No shit. The question was already massless.
If you’re zooming past the Earth at the speed of light headed straight at the Moon, you’ve got about 1 second to enjoy that before you make a very, VERY large crater.
If you change course and head straight at a frozen tardigrade, it will make a VERY large crater in you.
‘Speed of light’ compared to what? is what you need to worry about. Most things in the universe won’t be moving at the speed of light compared to you (or whatever you’re inside of), and when you run into them, you won’t last for long.
I haven’t seen the evidence of ‘water oceans’ out there that are about more than a few water ‘geysers’ spewing from below the frozen surfaces like our breaths on winter mornings.
Whenever I hear the words ‘water’ or ‘life’ in a message from NASA I think, ‘Hmmm… who stands to gain from this PR?’ (At least telescopes return great pix and -other, visible- evidence.)