Waterworld Possibility: Can Planet Be Covered in Water?

[saddlestone-man]

TL;DR Summary

Is it possible to have a planet completely covered in water?

Hello All

Is it possible to have a planet completely covered in water, like in the film Waterworld?

Is it the ultimate fate of the Earth for all the land to be eroded into the oceans, and all the ice to melt, giving a planet showing no land?

best regards ... Stef

<minor edit - mentor>

 

[anorlunda]

If Earth had more water, the oceans would be deeper. I don't know of any upper bound on how much water a planet (including Earth) could have. Therefore, I have to say yes, it is possible.

By the way, high mountains are constantly renewed by plate tectonics on Earth. The Himalaya Mountains for example, are growing higher faster than they erode.

I'm not sure what we know about the surfaces of Saturn, Uranus and Neptune. How do they define "surface"? are they liquid or gas?

 

[BillTre]

Is it possible to have a planet completely covered in water, like in the awful film Waterworld?

Although not a planet, but a moon of Saturn, Enceladus, is 500 kilometers in diameter, much like a planet, and covered by an ocean (which has a frozen surface). (You asked about water, not liquid water).

I see no real reason why such a thing could not happen to a larger body orbiting the sun.

 

[Klystron]

I'm not sure what we know about the surfaces of Saturn, Uranus and Neptune. How do they define "surface"? are they liquid or gas?

Although not a planet, but a moon of Saturn, Enceladus, is 500 kilometers in diameter, much like a planet, and covered by an ocean (which has a frozen surface). (You asked about water, not liquid water).

I see no real reason why such a ting could not happen to a larger body orbiting the sun.

Concur that moons of the 'icy giants' are more accessible to our technology than the outer planets. Slightly smaller than Luna and one of the 'roundest' objects in the solar system, Europa, smallest of the Galilean moons of mighty Jupiter, contains an immense ocean under an oddly patterned icy crust.

Similar to Enceladus (see above), Europa exhibits icy plumes shooting kilometers above the surface likely from cryogeysers . These water plumes allow exploration and sampling of these moons' oceans and the search for microscopic organisms without the necessity of landing and drilling.

 

[DennisN]

Is it possible to have a planet completely covered in water, like in the awful film Waterworld?

I see no real reason why such a thing could not happen to a larger body orbiting the sun.

Neither do I.

 

[anorlunda]

The movie Interstellar also had a water world.

 

[davenn]

Summary:: Is it possible to have a planet completely covered in water?

Is it the ultimate fate of the Earth for all the land to be eroded into the oceans, and all the ice to melt, giving a planet showing no land?

Tectonics would have to stop, and that isn't happening any time soon.
Then it would take 100's of millions of years after that for erosion to flatten the highpoints

 

[jim mcnamara]

A discussion of Earth before continents arose from plate tectonic activity, when Earth was almost all ocean -
https://Earth'sky.org/earth/when-Earth's-continents-rose-above-its-oceans

So Earth was very likely an ocean world. Plus during Cryogenean times, 'snowball' Earth came to be, when virtually all of the Earth surface was under ice.

See artist versions of Earth during the two glacial periods and impacts on life - Snowball Earth
https://en.wikipedia.org/wiki/Snowball_Earth

https://en.wikipedia.org/wiki/Cryogenian

 

[Keith_McClary]

Also: Waterworld was not a bad film.

It cost more Mars Pathfinder.

 

[Mary Conrads Sanburn]

U.S. Geological Survey
"Water, Water, Everywhere..." You've heard the phrase, and for water, it really is true. Earth's water is (almost) everywhere: above the Earth in the air and clouds and on the surface of the Earth in rivers, oceans, ice, plants, and in living organisms. But did you know that water is also inside the Earth? Read on to learn more.

[. . . ]

###
https://www.usgs.gov/special-topic/water-science-school/science/where-Earth's-water?qt-science_center_objects=0#qt-science_center_objects

 

[saddlestone-man]

Many thanks for the answers.

I guess if Earth still had a moon in this water-covered scenario, then the water would form a massive pair of bulges, locked to the Moon, which would circle the Earth once every 24 hours. Thinking about this, the bulges would be moving at 1,000 mph at the equator, but the motion of the water itself would be a combination of movement up and down, with a much slower (than 1,000mph) rotational speed. The Sun would complicate the overall tidal motion.

best regards ... Stef

 

[jim mcnamara]

FWIW - the length of day was much shorter early on, then tidal effects of the moon slowed Earth's rotation.
Which had another effect - more, shorter days packed into the same orbit for one year. During Carboniferous times the count of days per year was 385.

https://www.scientificamerican.com/article/earth-rotation-summer-solstice/

 

[jim mcnamara]

We are going into movie reviews here, which are really far outside the topic. Please take your perfectly good set of comments on movies to General Discussion. They will be a really good fit there. Not so, here.

 

[Mikestone]

No reason why not. Earth's diameter is abt 8000 miles, while the highest mountain peak is only five miles above sea level while the deepest ocean trench is only seven miles below it Were Earth a yard across, the difference between highest and lowest points would be only abt a thirtieth of an inch. Yet there is just enough water to cover three fourths of its surface while leaving the other one-fourth high and dry. I suspect we are a bit of a freak, and that on most planets which have oceans at all, these will cover the entire world.

 

[pinball1970]

Summary:: Is it possible to have a planet completely covered in water?

Hello All

Is it possible to have a planet completely covered in water, like in the film Waterworld?

Is it the ultimate fate of the Earth for all the land to be eroded into the oceans, and all the ice to melt, giving a planet showing no land?

best regards ... Stef

<minor edit - mentor>

We have lost a lot of water too according to the below

https://sciencenordic.com/chemistry...earth-has-lost-a-quarter-of-its-water/1462713

 

[Vanadium 50]

the highest mountain peak is only five miles above sea level

Or it's Mount Lamlam, 1300 feet above sea level but 37000 feet above the ocean floor.

 

[russ_watters]

I guess if Earth still had a moon in this water-covered scenario, then the water would form a massive pair of bulges, locked to the Moon, which would circle the Earth once every 24 hours. Thinking about this, the bulges would be moving at 1,000 mph at the equator, but the motion of the water itself would be a combination of movement up and down, with a much slower (than 1,000mph) rotational speed. The Sun would complicate the overall tidal motion.

How does that differ from the current situation besides that the tidal motion would be less interrupted?

 

[Astronautty]

A planet, sure. A life-bearing planet, not so much. I recall discussions (will make a small effort to find some and edit them into here) that weathering of rock exposed to atmospheric gases is necessary to create phosphates, in turn necessary for both DNA & RNA.

 

[fducedam]

Summary:: Is it possible to have a planet completely covered in water?

Hello All

Is it possible to have a planet completely covered in water, like in the film Waterworld?

Is it the ultimate fate of the Earth for all the land to be eroded into the oceans, and all the ice to melt, giving a planet showing no land?

best regards ... Stef

<minor edit - mentor>

Land errosion is only part of the cycle, land is also created by techtonic plates moving (subject to Coriolis effect and converction?).
Also as the ice melts water volume increase but land when not weight down by ice, raise at the same time so the ratio between emerged land and water volume may remains constant.

 

[Keith_McClary]

We have lost a lot of water too according to the below

These recent papers suggest that (besides or instead of into space) a lot of water has gone into
1) hydrating minerals in the mantle as the Earth cools
https://Earth'sky.org/earth/ancient-earth-water-world-global-ocean-harvard/
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020AV000323
2) forming the less dense rocks of the continental crust
https://theconversation.com/just-ad...ery-of-how-the-first-continents-formed-156845

 

[BillTre]

These recent papers suggest that (besides or instead of into space) a lot of water has gone into
1) hydrating minerals in the mantle as the Earth cools
https://Earth'sky.org/earth/ancient-earth-water-world-global-ocean-harvard/
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020AV000323
2) forming the less dense rocks of the continental crust
https://theconversation.com/just-ad...ery-of-how-the-first-continents-formed-156845

It has been estimated that about 1/2 the volume of the current oceans went into hydrating the mantle after the Earth was formed.
It also took a while (details disputed) or plate tectonics to get started and for continents (less dense rocks) to form.
This line of thought holds that the Earth was initially covered with an ocean with only an ocassional volcanic island sticking out of the water. These would be mantle plume volcanic systems like Iceland or Hawaii, not those associated with subduction zones (which require active tectonics).

Here is a reference on the initiation of plate tectonics.

 

[anorlunda]

Land errosion is only part of the cycle, land is also created by techtonic plates moving (subject to Coriolis effect and converction?).
Also as the ice melts water volume increase but land when not weight down by ice, raise at the same time so the ratio between emerged land and water volume may remains constant.

The Earth has ice and plate tectonics, but the OP was asking about a theoretical other planet.