Bio-Relevant Microscopic Liquid Subsurface Water in Planetary Surfaces?

A liquid is per definitionem able to flow and to continually deform under an applied force. This implies internal mobility, which is understood in terms of an organized relative motion of units like atoms, molecules or local (internally ordered) domains of them. It is this internal mobility, which makes liquids able to support internal transport of matter down to the atomic and molecular level. Life requires transport processes.