spirillum bacteria do not have endoflagella. Instead their flagella are external which is only connected to one end of the cell. While on the other hand spirochetes have endoflagellum which wrap around the cell body. See picture with prominent difference.
The difference between the spirochetes bacteria from the spirillum is that spirochetes have axial filaments while spirillum posses an external flagella.
This is not a question we can answer, this is a question only you can answer because it is asking for your personal belief on wether alien's exist outside of earth or not.
