How is the presence of water detected on celestial bodies and how is its state, solid or liquid, determined? Further related question, are the same methods used to detect the presence of water under the surface e.g presence of under surface, such as the possible water ocean on Europa?

How is the presence of water detected on celestial bodies and how is its state, solid or liquid, determined? In a related question, are the same methods used to detect the presence of subsurface water, e.g the subsurface ocean on Europa?

How present of water detected on celestial bodies? How it is determined its state solid or liquid? Further related question, are the same methods used to detect presence of water under the surface e.g presence of under surface water ocean on Europa?

How is the presence of water detected on celestial bodies and how is its state, solid or liquid, determined? Further related question, are the same methods used to detect the presence of water under the surface e.g presence of under surface, such as the possible water ocean on Europa?