roughly 78 % of the earth's surface is water.
roughly 78 % of the earth's surface is water.
what percentage of the earth's surface is water?
roughly 78 %
Na
Na
the concept of the habitable zone (or liquid water zone) defining a region where water can exist on the surface, is based on the properties of both the earth and sun. under this model, earth orbits roughly at the centre of this zone or in the "goldilocks" position. earth is the only planet in the universe confirmed to possess large bodies of surface water. venus is on the hot side of the zone while mars is on the cold side. neither are known to have persistent surface water, though evidence exists that mars did have in its ancient past, and it is speculated that the same was the case for venus. thus extrasolar planets (or moons) in the goldilocks position with substantial atmospheres may possess oceans and water clouds like those on earth. in addition to surface water, a true earth analog would require a mix of oceans or lakes and areas not covered by water, or "land".
earth analog