Why other planets does not have water, what caused so much water on earth, what we know about water (except chemical formula), what is water if you think globally in universe scale ?

But now planetary scientists in Japan suggest the oceans were actually "home-grown" – they may have formed because the young Earth had a thick

blanket of hydrogen, which reacted with oxides in the Earth's mantle to form lakes and seas.

"Water is essential for the origin and evolution of life," says Hidenori Genda from the Tokyo Institute of Technology. "Why does water exist on Earth, where

did it come from? These are fundamental questions for human beings."

Scientists believe that just after the Earth formed, it was very hot and dry. Theory also suggests that millions of water-rich comets and asteroids

bombarded our planet around 3.8 billion years ago, neatly explaining why oceans later appeared.

What's more, the ratio of deuterium – or "heavy hydrogen" because it contains a neutron in addition to a proton – to hydrogen in our sea water matches

the value found in water-rich asteroids, suggesting a common origin.

But Genda and his colleague Masahiro Ikoma suggest another possibility. They say the Earth could have had a thick atmosphere of hydrogen, which reacted

with oxides in the Earth's mantle to produce copious water.


http://space.newscientist.com/article/dn12693-earths-water-brewed-at-home-not-in-space.html

I do think something like this too I believe its because earth position at this alienation from sun caused chemical reaction or something that caused water to appear.

I heard there is some evidence that water was once on mars too, you think could it dry up or froze because sun changed its "shining" strength at some point of time and mars went out of the positive range and got frozen? Is there any evidence that sun was "shining" bit stronger or weaker in the past?

Also how do frozen water gets on asteroids and comets?

There is water everywhere in the solar system. Earth, mars, the moons of jupiter and saturn, and many other places.

As far as i know there could be hundreds\thousands even millions of planets similar to Earth.

There is water everywhere in the solar system. Earth, mars, the moons of jupiter and saturn, and many other places.
Have not heard about any planet in solar system that is PROVEN to have any water even frozen.

As far as i know there could be hundreds\thousands even millions of planets similar to Earth.Could be, but this is answer to what question?

Have not heard about any planet in solar system that is PROVEN to have any water even frozen.

Too bad. You're missing out on some really interesting discoveries.

Too bad. You're missing out on some really interesting discoveries.

I think i remember europa moon was mentioned in some documentary, but i am not sure, so whats planets proven to have ice?

This isn't the best, but it gives an idea.

http://www.waterencyclopedia.com/Re-St/Solar-System-Water-in-the.html

As a rule of thumb, it is probably safe to say that there are very few places that don't have H20.

A more interesting question is does anyone know of somewhere in the solar system that doesn't have water/ice/steam?

As a rule of thumb, it is probably safe to say that there are very few places that don't have H20.

A more interesting question is does anyone know of somewhere in the solar system that doesn't have water/ice/steam?
There probably aren't any that don't have some. Even the solar atmosphere has traces of H2O.

Hum,
Perhaps some metallic Apollo asteroid.

Could be, but this is answer to what question?

I was answering this:Why other planets does not have water

If they have water that alone would make them similar. Do you mean salt water, fresh water or something else?

The water that is present on the Earth was mostly delivered here by asteroid and cometary impacts.
The reason why it is still mostly here is perhaps due to the Earths magnetic field, which has protected the atmosphere from the solar wind, and the physical size, and orbit of the earth.
The earth's orbit also plays a part in the chances of that water being in liquid form. Another factor why it is in a liquid form is, i suspect, the presence of life forms, and tectonics.

Ivanovitch. Ceres in the asteroid belt, about 580 miles in diameter and speherical is said to have more FRESH water than Earth. We know there's a fair bit on one of the poles of the Moon where the sunlight never reaches. A thread started here the other day showed frozen water on the surface of Mars. We have found traces of water on at least one planet outside our solar system.

The water that is present on the Earth was mostly delivered here by asteroid and cometary impacts.How they happen to have water on them?

Same as how they happen to have silicon, carbon, methane, etc in them.

An alternative title for this thread could be `What caused XXXXX to appear on Earth?`.
(Replace the XXXXX with your substance or element)

Deleted.

However, to this day no-one has been able to say what dark energy is or where it comes from

I BELIEVE that dark matter is actually small ice crystals or some form of ice.

We have found traces of water on at least one planet outside our solar system.
Only one?

http://apod.nasa.gov/apod/ap071013.html

You really need to do a search for water in the solar system. It's everywhere, in solid and liquid form. We've found "traces" (!) on dozens of worlds. Wake up.

I BELIEVE that dark matter is actually small ice crystals or some form of ice.
That's nice. I BELIEVE it's the droppings from undiscovered intergalactic space cows.

There are a few hypotheses as to where the water on earth came from. We can speculate it came from somewhere else in the form of comets, but that doesn't explain where the water originally came from.

We can also speculate it came from earth itself.

When the earth was cooling, water vapor formed and condensed, clouds formed and for millions of years, continued to rain until the earth was an ocean planet.

An alternative theory to earth's origin has proto-earth as a large gas-giant planet, similar to Jupiter only smaller. It had a rocky/metallic inner core [like Jupiter], surrounded by a thick blanket of gas [like Jupiter]. The inner core formed when the early gases cooled to below the boiling point of the solids/metals and they rained out from the gas-ball giant, forming an inner liquid rocky/metallic core, which gravitationally differentiated into our present-day stratification.

The gas blanket was mostly hydrogen/helium [H/He], but other gases as well, including the much heavier H2O, which settled below the H/He outer blanket.

Under this theory, other stars formed in the vicinity of our Sun, in a "stellar nursery" like we nowadays see elsewhere in our galaxy. These were hot OB stars, much closer to our sun than they are nowadays, and they eventually boiled away [at about 1 foot/year of depth for a half billion years] the H/He blanket on proto-earth, leaving behind the much heavier H20. On Jupiter and Saturn, much of the original H/He blanket boiled away, but not all, leaving a distorted H-1/H-2 ratio. Likewise the murky interstellar clouds were driven off by the intense UV of the OB stars, and those stars eventually drifted away from our Sun, leaving us in our current condition.

One of the advantages of this theory is that it posits the formation of the moon along with earth from the same proto-cloud that gave rise to proton-earth, with a resultant moon in orbit about earth as the same orbital plane about the sun; a difficulty with the old planetoid striking earth and ejecting the moon idea. While the kinetics are difficult to explain in a short treatise, such a formation would also generate an enrichment in proto-earth of the heavier elements, and a deficiency in the moon. Thus, one would expect the moon to have relatively much less iron/nickel than earth, compared to the lighter elements [Aluminum, Oxygen, Silicon].

Thus, under this theory, the water has always been here since formation of proto-earth; no need to invoke comets striking the earth [which seems to be far too little, anyway].

The Earths formation is fairly well charted.

"abundances of elements in Lunar and Terrestrial material are sufficiently different to make it unlikely that the Moon formed directly from the Earth"
http://csep10.phys.utk.edu/astr161/lect/moon/moon_formation.html

The best theory is that a mars sized planet collided with eh the protaearth to form the moon.
The early solar system could have had as many as a 100 planets; most of which were expelled from the proto solar system.

The sun could well have formed in a stellar nursery and there is evidence that the solar system may have experienced the shockwaves of a supernova. The solar wind would have forced the lighter materials outwards. But even by that date the solar disk and protoplanets would have already formed. So it is possible that the water, and a thick atmosphere, was formed from out-gassings on the early molten earth.

But it should be said that the evidence from the number of impact scars on places like the moon show that the transportation of water by comets and asteroids is possible and sufficient to provide at least a good proportion of the Earths water.

Only one?

You really need to do a search for water in the solar system. It's everywhere, in solid and liquid form. We've found "traces" (!) on dozens of worlds. Wake up.
Traces could be left by whatever what about real presence of ice its found anywhere else than europa?

We can speculate it came from somewhere else in the form of comets, but that doesn't explain where the water originally came from.

Yes same question, if it comes from comets how it gets on them, what are comets/asteroids/meteors?

But it should be said that the evidence from the number of impact scars on places like the moon show that the transportation of water by comets and asteroids is possible and sufficient to provide at least a good proportion of the Earths water.
How much water (ice) moon has comparing to earth e.g. earth has 50% of surface filled with water, what about moon?

How long does moon exists?

Moon does not have atmosphere is it? It ever had one? What are other planets that dont have it?

How much water (ice) moon has

There is very little left but there will be deposits near the poles and primordial gas trapped within the moon.


How long does moon exists?

The moon is near enough the same age as the Earth.

Moon does not have atmosphere is it? It ever had one?

The moon may have had a atmosphere for a very brief period after the late heavy bombardment stage (say 3.9 billion years ago); however it would have been lost very quickly; almost as quickly as it formed. It would be interesting to look for evidence to see if any `seas` could have briefly formed. Today the moon retains a very, very, thin atmosphere; (the main reason why the moon lost it`s atmosphere is because of the moons low mass and lack of a magnetic field).

[/QUOTE]Today the moon retains a very, very, thin atmosphere;).[/QUOTE]

No. The moon has ZERO atmosphere - it's a vacuum as good as the vacuum between the planets.

Yes, the moon is distinctly different from the Earth in relative abundance of the elements - being relatively enriched in the lighter elements compared to the heavier. While some have suggested that implies a goodly portion of earth's "mantle" material was ejected [by planetoid impact] and then re-formed into a sphere, and underwent subsequent stratification, there is no plausible mechanism for such, and the likelihood of this occuring in the same plane as the earth's orbit about the sun is remote.

Conversely, if there were two centers of gravitational concentration orbiting about each other in the proto-cloud of hot gases that would have given rise to our earth/moon system, advanced dynamics suggests that the more massive one would become enriched in the heavier elements, while they were still in the gaseous phase. After they cooled to boiling and rained out, there would be no more intermingling of the materials between the two, and two separate planets would have been borne in orbit about each other, each having a thick sea of hot liquid H/He surrounding their liquid inner cores. The less massive one would have been relatively depleted in Iron/Nickel and the heavier elements, compared to the lighter Al, Si, etc., in which they would have been relatively enriched. While the lighter one [moon] would eventually have all of its H/He and other gases volatilized, leaving it airless, the heavier one [earth] would have lost all of its H/He, but some, if not most, of the heavier gases would have remained behind [H2O, SO2, CO2, NH3, etc.], though most would have reacted with other materials to form solids. Much of those gases would also have been entrained during the 'rain-out' phase of the liquid Fe/Ni and liquid Si/Al/O, where they still remain in the mantle region, though outgassing during volcanic eruptions.

superluminal. Water has been found on ONE planet 150 light years away. I know there are clouds of water ice crystals in space but of no use to us as they are far too rarified.

I mentioned a few places in the solar system in passing. There is no need to use your normal PIG manners to try and score points on the matter. I did not say there was none elsewhere. Certainly there is water on comets, if you don't mind some cyanide and such mixed in.

So if water is everywhere, show where it is on Mercury? Or maybe the gas giants where ammonia would instantly soak up all traces of water and so make it useless. Or how about Venus at near 400.C . Where's the water you say is everywhere? Perhaps you'd like to list those dozens of worlds since I don't know about them?

Go back to sleep. You're a waste of space.

kaneda,
Where's the water you say is everywhere? Perhaps you'd like to list those dozens of worlds since I don't know about them?
What you are personally ignorant of is not important, kaneda. Every planet, and many moons, in our solar system contains at least small amounts of water in one form or another. Venus is thought to contain very little at the present time in its evolution, as almost all has been lost as hydrogen due to its high heat. As a counter example, the scientific consensus is that there is a liquid ocean under the icy crust of the moon Europa, a huge amount of water.

Water has only been verified on one extra-solar planet, but it is thought to exist on most of the discovered worlds as a vapor. The problem is that most of those newly discovered planets are very distant from us and close to their parent stars, making accurate analysis of their spectrums for water vapor very difficult.

The moon has ZERO atmosphere - it's a vacuum as good as the vacuum between the planets.

i believe you are not aware of all the facts.

"The Moon has an atmosphere, but it is very tenuous.
Gases in the lunar atmosphere are easily lost to space. Because of the Moon's low gravity, light atoms such as helium receive enough energy from solar heating so that they escape in just a few hours."

Read more (http://www.lpi.usra.edu/lunar/missions/apollo/apollo_17/experiments/lace/)

"Composition of the tenuous lunar atmosphere is poorly known and variable,
these are estimates of the upper limits of the nighttime ambient atmosphere
composition. Daytime levels were difficult to measure due to heating and
outgassing of Apollo surface experiments."

Read more (http://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html)

Hum,
a nice article to bring people up to flank speed...

Read more (http://www.livescience.com/space/scienceastronomy/071224-mm-comet-mysteries.html)

(Summery for lazy people - `could be primordial or asteroids or both; we don't know for sure`)

i believe you are not aware of all the facts.

"The Moon has an atmosphere, but it is very tenuous.
Gases in the lunar atmosphere are easily lost to space. Because of the Moon's low gravity, light atoms such as helium receive enough energy from solar heating so that they escape in just a few hours."

Read more (http://www.lpi.usra.edu/lunar/missions/apollo/apollo_17/experiments/lace/)


Blobrana:

I stand technically corrected.

It depends upon one's definition of an "atmosphere", I suppose.

On the moon, of course, there will be a continuous infusion of solar-wind particles, as well as some releases of atoms from the surface with the impact of micrometeorites, etc. Even tiny "cometoids" might bring in frozen gases.

Once delivered to the moon, those gasses will then escape. The "atmosphere" would be the 'steady-state' amount determined by the infusion rate, and escape rate.

I suspect that the methane molecules that were detected were from such "cometoids", and not from out-gassing from the moon's interior.

In any event, one could also say that there is an "atmosphere" between the earth and the moon, since with adequate instrumentation one would almost certainly detect some atoms of gasses.

However, the moon's gravitational well would apparently keep the concentration slightly higher near the moon's surface, and thus technically one might refer to that as an "atmosphere"

Nice links, thanks.

Some people believe that God put the water here. :shrug:

Hum,

"Earth-Asteroid Collision Formed Moon Later Than Thought
The moon was formed from fragments of Earth after a collision with a giant asteroid relatively late in our planet's formation, new tests of moon rocks show.
The finding upends many of the prior theories for how the moon came to be, researchers say."

Read more (http://news.nationalgeographic.com/news/2007/12/071219-moon-collision.html)

Hum,

"Earth-Asteroid Collision Formed Moon Later Than Thought
The moon was formed from fragments of Earth after a collision with a giant asteroid relatively late in our planet's formation, new tests of moon rocks show.
The finding upends many of the prior theories for how the moon came to be, researchers say."

Read more (http://news.nationalgeographic.com/news/2007/12/071219-moon-collision.html)

Interesting. It looks almost like they are coming around to the idea that the earth-moon system continued to exchange material for quite some time [which under the theory I referenced above, accounts for an enrichment in the earth of the heavier elements]. They talk about exchange of material in the gaseous phase between both earth and moon - exactly the idea discussed by me earlier.

As they think about it more, they'll likely discard the need for an asteroid impact to eject the material, and instead recognize that if the earth-moon system formed like Jupiter and other gaseous planets, then the hot molten materials of the earth's interior were once slightly hotter, and in the gaseous phase, until they rained out forming a liquid ball in the interior of a dense [approximate density of 1.0] ball of hot liquid H/He.

You should do them a favor, and forward this link, as well as previous Sciforum postings of mine on the earth-moon formation, so they would have the benefit of this insight.

There are a few hypotheses as to where the water on earth came from. We can speculate it came from somewhere else in the form of comets, but that doesn't explain where the water originally came from.

We can also speculate it came from earth itself.

When the earth was cooling, water vapor formed and condensed, clouds formed and for millions of years, continued to rain until the earth was an ocean planet.

That was the explanation I read decades ago and I still see nothing wrong with it. The solar system is believed to have had a cold formation (ie: The sun did not ignite till later) which would have allowed light gases to form and mix near the centre of the solar system. When the sun ignited, the hard UV, charged particles, etc could have mixed the hydrogen and oxygen to form water.

Walter LW. The Earth-Moon system is thought to have formed around four billion years ago, so quite late. The impact would have meant a change of materials with gases and vapours/liquids mainly being pulled in by the more massive Earth.

The solar system is believed to have had a cold formation which explains the presence of lots of light gases close in to the sun. Internal planetary heat would have come later, through pressure of materials.

2inquisitive or is it 2rude? Someone made a statement to me which I believed was doubtful so I asked him to back it up. That is where you butted in with your irrelevances.

Water on Venus is where?

Europa is not a world but a moon. I would have thought that even you might have known this but:shrug:

I am of course aware of the problem with extrasolar planets as I think every other person on this board is.

Europa is not a world but a moon.
Err... so?

And I beg to differ. It may not be a planet, but it certainly is a world.

2inquisitive or is it 2rude? Someone made a statement to me which I believed was doubtful so I asked him to back it up. That is where you butted in with your irrelevances.

Water on Venus is where?

Europa is not a world but a moon. I would have thought that even you might have known this but:shrug:

I am of course aware of the problem with extrasolar planets as I think every other person on this board is.
This is a forum, kaneda. I do not need your permission to correct your ignorance of water in the universe.

'Water' can exist as a liquid, a solid, or in a gaseous state. It seldom exists in a 'pure' state. It can, and almost always does, have other elements mixed in it, or it can be present in other materials such as your own body.

You ask "Water on Venus is where?". It is mostly in the form of 'heavy water'. There is a form of hydrogen called deuterium that is heavier than 'regular' hydrogen and is not as easily lost from the planet's atmosphere. The VENUS EXPRESS probe found enough water vapor to cover the planet in an ocean with 1.2 inches of water if the vapor were condensed. Earlier theories assumed the water vapor in Venus's hot atmosphere would rise to the top of the atmosphere where it would be broken down into hydrogen and oxygen by radiation. They reasoned that the light hydrogen atoms would escape the planet's gravity, leaving almost no water on Venus. Venus Express found water vapor in Venus's atmosphere, so the theory is that it is likely to be mostly composed of the heavier deuterium type of hydrogen. Satisfied?

Europa is not a world but a moon. I would have thought that even you might have known this but
Either you have a reading comprehension problem, or you just state falsehoods hoping to fool some members. I have seen you do this to other posters also, so I suspect the latter. Here is a copy of my exact statement: the scientific consensus is that there is a liquid ocean under the icy crust of the moon Europa,

That was the explanation I read decades ago and I still see nothing wrong with it. The solar system is believed to have had a cold formation (ie: The sun did not ignite till later) which would have allowed light gases to form and mix near the centre of the solar system. When the sun ignited, the hard UV, charged particles, etc could have mixed the hydrogen and oxygen to form water.

It had nothing to do with the formation of the solar system, but instead the formation of earth when the crust was cooling and water was created in the form of condensation.

They have found that when stars form a ring of vapourised water (due to the temperature) exists in a cloud around the star, some of that water become asteroids when it freezes and is able to hit a planet.

Maybe that could be a explanation.

Walter LW. The Earth-Moon system is thought to have formed around four billion years ago, so quite late. The impact would have meant a change of materials with gases and vapours/liquids mainly being pulled in by the more massive Earth.

The solar system is believed to have had a cold formation which explains the presence of lots of light gases close in to the sun. Internal planetary heat would have come later, through pressure of materials.

I believe it is possible that the solar system formed from a cloud of hot H/He gas. We know that the gas that formed our solar system was enriched by one or more supernova explosions, admixing lots of HOT monatomic H/He, plus lots of HOT monatomic metals [Fe, Ni, U, Th, etc.]. If the supernova was not at the center of the cloud of H/He that it enriched, but offset from the center [or at the edge], it would have started the cloud spinning by the off-center impact of its ejecta.

Over millions of years, the spinning cloud would have also have had a uniform mixing of the supernova monatomic ejecta [hot gaseous monatomic metals, etc.], such that all parts of the spinning cloud would have equal ratios of all the isotopes of each element. If the supernova ejecta added just 0.1% to the initial cold cloud, by weight, but at a temperature of 1,000,000 degrees C, then the average temperature of the mixed cloud would be about 1,000 degrees C, neglecting cooling effects from radiative dissipation. It's likely that the supernova ejecta constituted more than 0.1% of the total mass, but it's not possible presently to calculate that exactly.

With a hot cloud of H/He, highly enriched in Ni/Fe [high metallicity], slowly spinning, it is plausible to expect that portions of the cloud would eventually form into gravitational centers, with a larger such center in the central region [proto-sun]. Eventually, those gravitational centers would form hot spherical balls of gas, in orbit about the more massive central ball of gas. Their internal temperatures would keep these large diameter, and even the central one would not yet be fusion ignited.

The smaller balls in orbit about the central ball would slowly dissipate their internal heat [dissipative radiation], and gravitationally contract. Eventually, the internal pressure would reach the point at which the metals, etc. would reach the boiling point, and they would be squeezed out of the gaseous phase, and form drops of liquid, which would then rain to the center of the cloud, forming a ball of liquid. Finally, even the H/He would liquify, with the protoplanet thus being a ball of inner liquid metals/rocks, surrounded by mostly H/He in liquid form to a depth of a hundred thousand miles or so.

The more massive such gas balls [Jupiter, Saturn], even after a half billion years of UV irradiation from other nearby stars then forming, retain much of that outer H/He blanket. The smaller ones [moons, inner planets] lost all of those gases due to such UV irradiation [plus the irradiation from the sun, which would have been newly ignited].

Anyway, that's what the scenario would be like if one had such a cloud of initially cold H/He, subsequently enriched and heated with hot Ni/Fe from a nearby supernova.

How do you suppose, under your scenario, that the cloud got so cold?

well if u get up in the morning and see the dew or the condensation and i guess one can see how that got here ..would have to be very old to have water from condensation
so maybe it was ahmm frozen hahaha

caused by gasses

have a look in ur freezer
when thawed out well its liquid

ur freezer is working on diff gasses
when one dont work no more ur freezer dont work

same as our poles when one dont work the earth dont work

This is a forum, kaneda. I do not need your permission to correct your ignorance of water in the universe.

'Water' can exist as a liquid, a solid, or in a gaseous state.


Water is a gas? And you have the cheek to call me ignorant.

HEAVY water in the uppermost reaches of the atmosphere is hardly "water on Venus" except in the most abstract circumstance.

We were talking worlds and you butted in and started going on about moons. Duh!

Walter LW. If you have a "burning sun" from the first moment of formation of a solar system, then a strong solar wind is going to throw the lighter gases to the outer reaches of the solar system. The cold start allowed ice cores to form to start planet formation :

http://stardate.org/resources/ssguide/planet_form.html

A nearby supernova would have started the process off by sending compression waves through a cold nebula.

They have found that when stars form a ring of vapourised water (due to the temperature) exists in a cloud around the star, some of that water become asteroids when it freezes and is able to hit a planet.

Maybe that could be a explanation.


There is still a fair bit of ice about in the asteroid belt and elsewhere. The state of our Moon, other moons, Mercury, etc show that there was a massive bombardment of the early solar system which certainly could have rained ice down on the early Earth.

Water is a gas? And you have the cheek to call me ignorant.

HEAVY water in the uppermost reaches of the atmosphere is hardly "water on Venus" except in the most abstract circumstance.

We were talking worlds and you butted in and started going on about moons. Duh!
kenada,
Water is a gas? And you have the cheek to call me ignorant.
Yes, water can exist in three states, as a solid (ice), liquid, or a gas (water vapor). That is taught in junior high, but you must have been asleep in class.
HEAVY water in the uppermost reaches of the atmosphere is hardly "water on Venus" except in the most abstract circumstance.
What makes you think the heavy water is only in the uppermost reaches of Venus's atmosphere? What makes you think heavy water is an abstraction? What makes you think only heavy water is in Venus's atmosphere? Deuterium is an isotope of hydrogen, it has one proton in its nucleus the same as regular hydrogen, but with the addition of a neutron. Heavy water is chemically the same as regular (light) water. You jump to conclusions on a regular basis with no other knowledge than your own false speculation. It is OK to be ignorant in certain aspects of science, no one person knows it all, but you pretend to be knowledgeable in things you don't have a clue about. A forum's greatest value is in its contributions from many members. Each member may sometimes have a bit of information not known to the general forum. You asked where the water on Venus was. In the older textbooks, the theory was that almost all the water had escaped from Venus's atmosphere. New, experimental measurements made by the Venus Express indicate much more water vapor in Venus's atmosphere than earlier theory suggested. The new theory is that there is a much higher percentage of heavy water than was previously considered. The Venus Express can not distinguish between heavy water and light water, only measure water in the atmosphere. The heavy water is a perfectly logical theory, but the only known fact is a much higher concentration of water vapor in the atmosphere than theorized.

Water is a gas? And you have the cheek to call me ignorant.
Oops. Be very careful big K. When we here talk about water, we mean H2O, which, as 2inq points out, can come in three forms. You need to be specific if you're just talking about liquid oceans of water. Clearly, the earth is the only known "world" to have exposed liquid water in ocean-sized quantities. But Ice on the other hand in known on many "worlds" and sub-ice liquid water and even "oceans" are now known on several.

We were talking worlds and you butted in and started going on about moons. Duh!
Well, since "world" is commonly used do describe anything from jovian sized planets to little asteroids, and several moons in our solar system are bigger than the planet mercury (ganymede for example and titan - almost the size of mars!), I'd say these were worlds.

If you mean officially recgonized planets, then say planets.

Are there other planets with an atmosphere and condensed vapor that forms water like on earth?

Are there other planets with an atmosphere and condensed vapor that forms water like on earth?

:scratchin: u, i'm gonna say probably.:shrug:

Are there other planets with an atmosphere and condensed vapor that forms water like on earth?
Not water, no. We know of no other "worlds" that rain liquid water that gathers in open pools. However...

Titan is eerily earth-like in appearance, with rivers and huge lakes of what is almost certainly liquid methane, which almost certainly come from a "rain" of condensed methane vapor in it's atmosphere.

Very cool.

Perhaps the link below will provide some insight:

http://dsc.discovery.com/news/afp/20030922/universe.html

:scratchin: u, i'm gonna say probably.:shrug:
Well, not in our solar system at least. But I'd agree with "probably" as far as the apparently vast number of other "solar" systems out there. We've discovered hundres of extrasolar planets just in the past few years without even looking beyond our local little galactic neighborhood.

Also, vey cool.

Perhaps the link below will provide some insight:

http://dsc.discovery.com/news/afp/20030922/universe.html
Right. See my post above. I think we're talking in the solar system here.

Not water, no. We know of no other "worlds" that rain liquid water that gathers in open pools. However...

.

So why do we have it? Whats different about our atmosphere that we have water?

So why do we have it? Whats different about our atmosphere that we have water?
Well, lots of planets have water (if you've followed the rest of the thread). But the conditions for liquid surface water appear to be unique to the earth (in our solar system).

The average temperature and pressure are such that liquid water can exist on most of our planet. Call it luck. The earth happens to be in just the right "habitable zone" for a star of sol's type.

So its just dumb luck then. Cool.

Right. See my post above. I think we're talking in the solar system here.

S.A.M didn't say but maybe thats waht she meant. Ether way have a look at Gliese 581.

Computer models predict Gliese 581 C is either a rocky planet like Earth or a waterworld covered entirely by oceans.

http://www.space.com/scienceastronomy/070424_hab_exoplanet.html

S.A.M didn't say but maybe thats waht she meant. Ether way have a look at Gliese 581.

http://www.space.com/scienceastronomy/070424_hab_exoplanet.html
Yep. I know of it. Very cool stuff!

So its just dumb luck then. Cool.
Yep. Simple as that.

Pisses you off, don't it?

Yep. Simple as that.

Pisses you off, don't it?

You say tomayto...:shrug:

There sure seems to be a lot of dumb luck floating around. :p

You say tomayto...:shrug:

There sure seems to be a lot of dumb luck floating around. :p
Not really. Out of 9 (oops, 8 now...) planets in our solar system, only one has the right conditions. Not very good luck for the rest of them, huh?

And if we look at the distribution of other "earths" in the galaxy (as we get better telescopes with better spectrometers) and find they are few and far between (which I suspect) then the luck wouldn't be very good there either, would it?

Do you know the theory of the "enumeration of favorable circumstances" as it applies to your own perception of just how lucky or "special" you might be?

Not really. Out of 9 (oops, 8 now...) planets in our solar system, only one has the right conditions. Not very good luck for the rest of them, huh?

And if we look at the distribution of other "earths" in the galaxy (as we get better telescopes with better spectrometers) and find they are few and far between (which I suspect) then the luck wouldn't be very good there either, would it?

Do you know the theory of the "enumeration of favorable circumstances" as it applies to your own perception of just how lucky or "special" you might be?

I know that if I attributed any of my research results to luck and said that everyone else who did not have the same results were just not favored by the right natural alignment of the sun and stars, it would not help me any. :p

Well, lots of planets have water (if you've followed the rest of the thread). But the conditions for liquid surface water appear to be unique to the earth (in our solar system).

The average temperature and pressure are such that liquid water can exist on most of our planet. Call it luck. The earth happens to be in just the right "habitable zone" for a star of sol's type.
You are correct if you are speaking of water staying in the liquid state for a length of time on our solar system bodies at this stage of evolution. There is evidence that both Mars and Venus had oceans of liquid water in the past. There is further evidence that Mars may have liquid water on the surface at certain latitudes for brief periods of time at the present stage of its evolution. I'm not sure how many have seen the reports by NASA, but here is a cut & paste and link to some of NASA's evidence:
"The shapes of these deposits are what you would expect to see if the material were carried by flowing water," said Michael Malin of Malin Space Science Systems, San Diego. "They have finger-like branches at the downhill end and easily diverted around small obstacles." Malin is principal investigator for the camera and lead author of a report about the findings published in the journal Science.

The atmosphere of Mars is so thin and the temperature so cold that liquid water cannot persist at the surface. It would rapidly evaporate or freeze. Researchers propose that water could remain liquid long enough, after breaking out from an underground source, to carry debris downslope before totally freezing. The two fresh deposits are each several hundred meters or yards long.
http://www.nasa.gov/mission_pages/mars/news/mgs-20061206.html

I know that if I attributed any of my research results to luck and said that everyone else who did not have the same results were just not favored by the right natural alignment of the sun and stars, it would not help me any. :p
Do you see the incredible bias in your very speech toward being "favored" and such? The idea of some directing entity infects every subject you seem to come into contact with. There is no implication of us being "favored" at all. We just are. "Luck" is nothing more than a human attempt to apply some feeble attribute of determinism to a harsh and ultimately random universe.

"We sure are lucky to be here"

Really? No. We're just here. If the underlying rules of the universe permit some portion of planets to be in certain orbits that allow for surface liquid water and the subsequent development of life, then it would be even more astounding if we weren't here!

You are correct if you are speaking of water staying in the liquid state for a length of time on our solar system bodies at this stage of evolution. There is evidence that both Mars and Venus had oceans of liquid water in the past. There is further evidence that Mars may have liquid water on the surface at certain latitudes for brief periods of time at the present stage of its evolution. I'm not sure how many have seen the reports by NASA, but here is a cut & paste and link to some of NASA's evidence:

http://www.nasa.gov/mission_pages/mars/news/mgs-20061206.html
Yes. That's what I'm talking about and yes I've seen this data.

[QUOTE][What caused the water to apear on Earth? /QUOTE]

Magic beans!:D

How do you suppose, under your scenario, that the cloud got so cold?


A typical dust/gas cloud that was "activated" by a nearby nova/super-nova into forming a system.

superluminal. I don't mind someone adding to a debate (even if I don't agree with them) but not when they butt in to try and score points as 2inq did.

Sure there's hidden water about, even bound in rocks, etc if you want to go that far.

I did check with dictionary.com and moons are not worlds, but who cares?

2inquisitive. I was taught at junior school quite a number of decades ago now that a gas is something that is not liquid at above -40.C (ie: CO2). Anything that is liquid above -40.C is a vapour. Big difference.

Water turns into steam vapour at 100.C . Venus has a temperature of about 450.C . While water molecules could be held in place because they are unable to escape Venus's gravity, the uppermost reaches of it's atmosphere are the nearest they are ever going to get to being "on Venus". Venus has water, the same as sugar has water.

If I regularly make "false speculations", why do you not point them out? Just making an empty statement that I am regularly wrong makes you look like an idiot.