Above: This mosaic shows 112 galaxies out of an estimated 100 billion+ galaxies of the visible Universe. A galaxy usually harbours some 100 billion stars more or less similar to our Sun.

There are some six galaxies per every person on Earth.

...and this is only the visible Universe...


Water Fact File for the Universe

The Bottom Line:

Suffice to say, lots of water!


Findings from Dr Kotwicki's 1991 Paper:

Everyone who ever studied astronomy for fun or profit knows that the Universe is big. What conclusions could be drawn from this fact in respect to water?

As hydrogen (from Greek "hudor" - "water") is so plentiful in the Universe, the synthesis of water depends on the supply of oxygen. The quantity of this element, recalculated from Press and Siever (1978) and shown in Table 5 is probably underestimated. Just recently, for example, astronomers have found that oxygen exists in the so-called "cooling flows" - a  heavy rain of gas that is falling into many galaxies from the supposedly empty space around them. The amount of this intergalactic "rainfall" can be anything from one to 1000 solar masses per galaxy each year, which is sufficient to double the mass of the largest galaxy over the lifetime of the Universe.

Table 5. Abundance of the principal elements in the Universe
expressed as the number of atoms relative to a base of 1000 atoms of oxygen
(recalculated from Press & Siever, 1978)


Atomic number

Atomic weight

Abundance in the Universe




2 000  000




150  000




1 000





























In any case, oxygen is the third most abundant element in the Universe, ranked between the inert gases helium and neon. What is more, oxygen reacts readily with the most abundant hydrogen, creating water, which in turn is one of the most stable chemical molecules. It should not be surprising then if water is found to be one of the most common molecules in this Universe. If, for example comets - which are mostly water ice - form a significant constituent of the "missing mass" which may account for 90% of the Universe, the remote unchartered (albeit mostly frozen) oceans are truly unimaginably big.

Just how big they are remains largely unclear. Considering the visible Universe, stars are numerous (at 1022 their quantity  exceeds the number of grains of sand on Earth) and in various stages of development. Many of them may posses planets  which seem to be a standard by-product of the star formation. Seas, lakes and rivers are more likely to be found in spiral arms of galaxies: their nuclei are more star-compacted and have much less stable (and hence suitable) conditions for planet formation and development.

Our knowledge of "dark matter" or "missing mass" is still very incomplete. The critical density of the Universe (necessary to stop the Big Bang expansion) works out at about 3 atoms m-3. All matter detected to date falls short of this critical value by a factor of about ten: as there is also ten times as much dark matter exerting its gravitational influence as there is matter in  the form of bright stars, we conclude that the bright stars represent only 1% of the Universe. If our Sun were a typical star, the amount of water which could be attributed to the visible matter would be significant (>1025 Earth masses) although dispersed: a glass of water requires on average 1021 km3of space to materialise. If dark matter prevails, this amount would be much greater.

Giant molecular clouds with densities from 100 to 10 000 atoms cm-3 and masses exceeding millions times the mass of the  Sun are common features in galaxies. Water molecules in them have been detected. Does water ice in the form of comets initiate the birth of stars in these clouds, acting as nuclei of contraction? How does it affect the creation of planets from rotating nebulae? The questions are many, so far unsolved. Radio astronomers have found that clouds of gas in space consist largely of hydrogen molecules and carbon monoxide. Gas that condenses near a star - at the distance of our four gaseous giants - is heated by the star to form low-density ices of methane and water, so a constant supply of these substances appears to be assured.

New announcements are made almost daily and the foundations of our knowledge are trembling. Even the Big Bang theory, so secure still, may fall as an aftermath of the recent commissioning the Hubble Space Telescope. Just recently, for  example, astronomers discovered in the Virgo cluster, some 65 million light years from Earth, a giant hydrogen cloud that could be an unborn galaxy and possibly provide the first evidence that more star systems are being formed. Conventional wisdom used to place the birth of galaxies in some conveniently remote past.

Trying to establish a temporal pattern of occurrence of water in the Universe requires some stretching of imagination and a  fair dose of conjecture. Considering the Big Bang scenario, water did not exist until a first generation of stars exploded,  which could happen fairly quickly, in millions of years only after their condensation from primordial hydrogen. Since then, the amount of water increased steadily to its present (unknown) quantity and is increasing now: this thesis will be probably easier to prove than the stability of the Earth's water resources.

Considering the future of water, it appears quite poor in the closed Universe scenario, when billions years from now the matter, space and time will collapse in a Big Crunch and the existing laws of physics will loose any meaning. Mathematicians so far cannot invent a re-emergence of a new, fresh Universe from this unfortunate state. The future looks  somewhat better in the open Universe scenario, in which the Universe would expand forever, carrying its cooling and  ultimately frozen assets, including water, towards infinity or concluding proton disintegration, which some scientists believe could happen on a very respectable but little comprehensible time scale of 106000 years.


Latest Findings about Water in the Universe:



Water in the Universe
Water in the Universe

Please contact our Webmaster with questions or comments. © 1991-2005 Dr Vincent Kotwicki.
All rights reserved. Designed by
k26 Studios