3 ms·

Hm... Cryogenic hydrogen?

• remarkEon 7y ago
  Tin foil hat time: What kind of exotic or near-future engine tech could produce a signature like that? (No I don't think it's Aliens ... if it's Aliens, they'd have the means to travel interstellar distances and if they can do that then surely they can keep themselves hidden).
  • karmakaze 7y ago
    Not suggesting either way but the logic is flawed. Presupposes desire to be hidden. Possible that the entire purpose is to gently assert presence.