[ShawnW (OP)]

Can the asteroid belt be the missing planet in our solar system? Could the Earth the moon and Mars have been moons of this planet(if existed). If so, could earth have been a frozen moon of this planet and that is where we are getting all our water? It just seems very unlikely that asteroids brought all the earth's water and no water on the moon or mars? Did earth and the planet Theia collide to give us our orbit or could have been when the missing planet met it's demise? Also, maybe that is why our solar system's planets orbits or where they are located not the same as most of the other planets in other solar systems. Such as why is Jupiter larger then the other gas giants, but closer to the sun?

[Janus]

Can the asteroid belt be the missing planet in our solar system? Could the Earth the moon and Mars have been moons of this planet(if existed). If so, could earth have been a frozen moon of this planet and that is where we are getting all our water? It just seems very unlikely that asteroids brought all the earth's water and no water on the moon or mars? Did earth and the planet Theia collide to give us our orbit or could have been when the missing planet met it's demise? Also, maybe that is why our solar system's planets orbits or where they are located not the same as most of the other planets in other solar systems. Such as why is Jupiter larger then the other gas giants, but closer to the sun?

The entire mass of the asteroid belt only amounts to ~ 4% of the mass of the Moon.  So, no there never was any really massive planet there.   
 Mars used to have water, but because of its small size, lost most of it over time.  The Moon, being smaller still and even closer  to the Sun, can't hold on to any significant atmosphere, which would be required to have liquid water.  There may be some ice deposits on the Moon in deep shadowed regions which never get any sunlight.

[guest45734]

 Mars used to have water, but because of its small size, lost most of it over time.  The Moon, being smaller still and even closer  to the Sun, can't hold on to any significant atmosphere, which would be required to have liquid water.  There may be some ice deposits on the Moon in deep shadowed regions which never get any sunlight.

Water has been discovered on the moon according to NASA https://www.independent.co.uk/news/science/moon-ice-discovery-water-frozen-nasa-craters-space-a8500566.html

[Petrochemicals]

If there was a planet there, which i believe has been disproved as the asteroids are some of the oldest forms in the solar system so the asteroids have been around along time and formed the belt without a planet to affect them, or if there was enough matter in the belt to make a planet, the majority has been lost to other areas.

The migration of jupiter has been one suspect for the missing planet, mars could be well a lost moon of jupiter and jupiters moons captured planets.

https://www.space.com/28901-wandering-jupiter-oddball-solar-system.html

Edit

The water on the moon is subsurface ice i believe

[chris]

The entire mass of the asteroid belt only amounts to ~ 4% of the mass of the Moon

That's interesting, thanks; I didn't know that - have you got a reference for who / how that was calculated?

[chiralSPO]

The entire mass of the asteroid belt only amounts to ~ 4% of the mass of the Moon

That's interesting, thanks; I didn't know that - have you got a reference for who / how that was calculated?

I am not sure how this was calculated (presumably a survey), but Ceres is often quoted as making up about half of the mass of the asteroid belt, and it has about 2% the mass of the moon. This is in good agreement with the 4% estimate provided above...

[evan_au]

Wikipedia agrees on the mass being around 4% of the Moon, but has a slightly different distribution of mass...

About half the mass of the belt is contained in the four largest asteroids: Ceres, Vesta, Pallas, and Hygiea. The total mass of the asteroid belt is approximately 4% that of the Moon, or 22% that of Pluto, and roughly twice that of Pluto's moon Charon (whose diameter is 1200 km).

See: https://en.wikipedia.org/wiki/Asteroid_belt

This list suggests that Ceres represents about 31% of the mass of the entire asteroid belt; the top 19 account for around 62% of the mass of the asteroid belt. They also estimate the precision of the measurement, which is derived from the orbital perturbations caused on other asteroids by their gravity. It gets harder to measure these perturbations the smaller the asteroid...

https://en.wikipedia.org/wiki/List_of_exceptional_asteroids#Most_massive

[Petrochemicals]

To be honest shaun a far more plausable and non defunct theory is outlined here.

https://www.thenakedscientists.com/forum/index.php?board=12.0

[ShawnW (OP)]

Thank you for the update, but any specific topic under https://www.thenakedscientists.com/forum/index.php?board=12.0 that I should look at?
Also, do you have more answers on the volume of water on earth compared to other planets?

[Petrochemicals]

Thank you for the update, but any specific topic under https://www.thenakedscientists.com/forum/index.php?board=12.0 that I should look at?
Also, do you have more answers on the volume of water on earth compared to other planets?

Sorry shaun, technologica malfunction

https://www.thenakedscientists.com/forum/index.php?topic=72981.0