A conditional definition

The habitable zone describes distances from a star where a planet could sustain liquid water on its surface given suitable atmospheric conditions. Its boundaries depend on the star and assumptions about the planet.

[1] NASA

Where the shorthand falls short

Being inside this zone does not prove that a planet has an atmosphere, water or life. Subsurface oceans also illustrate why surface-water criteria do not exhaust every potentially habitable environment.

[1] NASA[2] NASA/JPL

Connected knowledge

europa

RELATED TO · A subsurface ocean illustrates a potential environment beyond a surface-water criterion.

Established
trappist 1

RELATED TO · Planetary environments are assessed using conditional habitability concepts.

Established
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