The latest information suggests that Earth's water came from Meteorites . The Moon was also bombarded by Meteorites and yet it has no water. Is this because it lacks an atmosphere and its water was lost in space ?

On further thought on this matter, it occurred to me that Mars has an atmosphere and yet it has no oceans either, just like the Moon . So Mars I assume was bombarded by meteorites, just like the Earth was and it has a stronger gravity than the Moon, yet it doesn't have oceans either ? So what happened ?

  • $\begingroup$ You should include a reference to where you are getting "the latest information." $\endgroup$ Commented Jan 12, 2015 at 15:53
  • $\begingroup$ I got this information from a Space Documentary that I saw on television. $\endgroup$
    – Peter U
    Commented Jan 12, 2015 at 15:59
  • $\begingroup$ The latest science on comets/water/earth $\endgroup$
    – db9dreamer
    Commented Jan 14, 2015 at 21:37

2 Answers 2


It would have to be a big meteorite to supply the quantaties we have here and therefore support the nuclear break down theory.ie- hydrogen to helium etc.

In respect of delivery by cosmic objects, the atmospheric pressure on the moon would result in a low boiling point and the evaporation velocity(due to low gravitational attraction) would exceed the escape velocity of the moon and meet with no atmospheric resistance. This is the way I see it. The body of water, although spread over the surface, would consider itself as an independent body and have its own "existence parameters" with regards to its environment.

The ability of Mars to retain water vapour is much reduced by its lower gravitational strength and atmospheric density. Can water exist at these parameters continuously, the evidence shows not.

  • $\begingroup$ That is what I figured also that the water would escape from the Moon because it has no atmosphere but what about Mar's, it has an atmosphere. Why doesn't Mars have Oceans like the Earth ? $\endgroup$
    – Peter U
    Commented Jan 13, 2015 at 23:59
  • 1
    $\begingroup$ Why not combine your answers? $\endgroup$
    – HDE 226868
    Commented Jan 14, 2015 at 16:15
  • $\begingroup$ answers combined $\endgroup$
    – James K
    Commented Apr 15, 2017 at 11:28

Your latest information is not a clear image of H2O economy of the evolving earth. enter image description here

it takes a lot of hot and cold and solar wind to dry a planet into a rock, a solar system planet's natural state is to have a lot of ices, if it wasn't for atmospheric loss.

You can see that there are vast amounts of H and O inside the sun and solar system, and the earth would have constantly received large volumes of water throughout it's formation.

Solar radiation and freezing conditions evaporate/sublimate water and volatile gaseous chemistries, so inner planets would have more water if it were not for solar radiation and dry frost, because it sends the masses of water back out into space. H and O bond well with other minerals and they exist in many acids and minerals more prevalently than in water, i.e. there is more water 100ds of kilometers inside the planet than in the oceans.

Hydrogen and Oxygen are some of the lightest elements and most likely to escape to the high atmosphere, so the end balance of the planets has been an equation between massive constant arrival of water and massive constant evaporation, where only the earth has had ambient temperature, high planet gravity, and the magnetic field to keep water as oceans, rather than H in ices and acids.

The atmospheric losses can be more of light Hydrogen than Oxygen, Venus has masses of atmospheric oxygen and almost no hydrogen.


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