All life on Earth that we have found so far lives in the temperature range of liquid water, ie zero to 100 deg centigrade. What other liquids could sustain life forms outside this temperature range? and where might these conditions be found?

bob(from black rock) said:

All life on Earth that we have found so far lives in the temperature range of liquid water, ie zero to 100 deg centigrade. What other liquids could sustain life forms outside this temperature range? and where might these conditions be found?

The range is a bit beyond that, bob. Ocean vents get above 100 degrees.

Ammonia is often suggested as a candidate, remaining liquid between -78 & -33C. But it’s not as generally useful as water as a biological solvent. There’s plenty of ammonia in the atmospheres of Jupiter and Saturn, probably in the form of ice clouds.

morrie said:

bob(from black rock) said:

All life on Earth that we have found so far lives in the temperature range of liquid water, ie zero to 100 deg centigrade. What other liquids could sustain life forms outside this temperature range? and where might these conditions be found?

The range is a bit beyond that, bob. Ocean vents get above 100 degrees.

OK, thanks morrie, but it still involves liquid water.

Extremophiles.

I think they are out of that range.

Bubblecar said:

Ammonia is often suggested as a candidate, remaining liquid between -78 & -33C. But it’s not as generally useful as water as a biological solvent. There’s plenty of ammonia in the atmospheres of Jupiter and Saturn, probably in the form of ice clouds.

Thanks Bubbles, I wonder if there are any bodies with hydro carbon lakes? or atmospheres?

Plenty of liquid hydrocarbons on Titan, cycled from the surface to clouds and back again. Very cold surface though.

This question is addressed quite well in chapter 6 of this document, starting at page 69

http://ecoversity.org/archives/LOLPS.pdf

They suggest some interesting possibilities such as sulphuric acid and formamide.

My, this spell checker needs to update the spelling of sulphuric.

Bubblecar said:

Plenty of liquid hydrocarbons on Titan, cycled from the surface to clouds and back again. Very cold surface though.

That circulatory action is similar to the hydrological cycle here, so living organisms are not out of the question?

Wikipedia has a nice article on this topic.

Hypothetical types of biochemistry

Here are some excerpts relating to water and alternative solvents.
Wikipedia said:

The idea that an extraterrestrial life-form might be based on a solvent other than water has been taken seriously in recent scientific literature by the biochemist Steven Benner, and by the astrobiological committee chaired by John A. Baross. Solvents discussed by the Baross committee include ammonia, sulfuric acid, formamide, hydrocarbons, and (at temperatures much lower than Earth’s) liquid nitrogen, or hydrogen in the form of a supercritical fluid.

[…]

Some of the properties of water that are important for life processes include a large temperature range over which it is liquid, a high heat capacity (useful for temperature regulation), a large heat of vaporization, and the ability to dissolve a wide variety of compounds. Water is also amphoteric, meaning it can donate and accept an H+ ion, allowing it to act as an acid or a base. This property is crucial in many organic and biochemical reactions, where water serves as a solvent, a reactant, or a product. There are other chemicals with similar properties that have sometimes been proposed as alternatives. Additionally, water has the unusual property of being less dense as a solid (ice) than as a liquid. This is why bodies of water freeze over but do not freeze solid (from the bottom up). If ice were denser than liquid water (as is true for nearly all other compounds), then large bodies of liquid would slowly freeze solid, which would not be conducive to the formation of life.

Not all properties of water are necessarily advantageous for life, however. For instance, water ice has a high albedo, meaning that it reflects a significant quantity of light and heat from the Sun. During ice ages, as reflective ice builds up over the surface of the water, the effects of global cooling are increased.

Also, when salts dissolve in water they ionise, eg common salt, NaCl, splits up into Na⁺ and Cl^- ions. This process is very important for a lot of chemical reactions. Other liquids can also do this, but it’s not so common, eg, it doesn’t happen with simple hydrocarbons.

bob(from black rock) said:

Bubblecar said:

Plenty of liquid hydrocarbons on Titan, cycled from the surface to clouds and back again. Very cold surface though.

That circulatory action is similar to the hydrological cycle here, so living organisms are not out of the question?

This Wiki article explores the question:

Life on Titan

From Wikipedia, the free encyclopedia

Whether there is life on Titan, the largest moon of Saturn, is at present an open question and a topic of scientific evaluation and research.

Titan is far colder than Earth, and its surface seems to lack liquid water; factors which have led some scientists to consider life there unlikely. On the other hand, the following points have been made in favor of Titan’s suitability to sustain some form of life:
Titan appears to have lakes of liquid ethane or liquid methane on its surface, as well as rivers and seas, which some scientific models (still tentative and debated) suggest could support non-water-based life.
It has also been suggested that life may exist in a sub-surface ocean consisting of water and ammonia. Recent data from NASA’s Cassini spacecraft have strengthened evidence that Titan likely harbors a layer of liquid water under its ice shell.
Titan is the only known natural satellite (moon) in the Solar System that is known to have a fully developed atmosphere that consists of more than trace gases. Titan’s atmosphere is thick, chemically active, and is known to be rich in organic compounds; this has led to speculation about whether chemical precursors of life may have been generated there.
The atmosphere also contains hydrogen gas, which is cycling through the atmosphere and the surface environment, and which living things comparable to Earth methanogens could combine with some of the organic compounds (such as acetylene) to obtain energy.

In June 2010, scientists analysing data from the Cassini–Huygens mission reported anomalies in the atmosphere near the surface which could be consistent with the presence of methane-producing organisms, but may alternatively be due to non-living chemical or meteorological processes. The Cassini–Huygens mission was not equipped to provide direct evidence for biology or complex organics.

More: http://en.wikipedia.org/wiki/Life_on_Titan

bob(from black rock) said:

Bubblecar said:

Plenty of liquid hydrocarbons on Titan, cycled from the surface to clouds and back again. Very cold surface though.

That circulatory action is similar to the hydrological cycle here, so living organisms are not out of the question?

Not totally, but those hydrocarbons don’t do the ionisation thing I mentioned in my previous post. And they sink when they freeze, which is rather inconvenient for any life forms who are trying to live in hydrocarbon lakes and seas.

PM 2Ring and all others, thankyou for your contributions on this topic, there is much more info there than I expected, ta, bob.

Study tests theory that life originated at deep sea vents

One of the greatest mysteries facing humans is how life originated on Earth. Scientists have determined approximately when life began (roughly 3.8 billion years ago), but there is still intense debate about exactly how life began. One possibility – that simple metabolic reactions emerged near ancient seafloor hot springs, enabling the leap from a non-living to a living world – has grown in popularity in the last two decades.

Recent research by geochemists Eoghan Reeves, Jeff Seewald, and Jill McDermott at Woods Hole Oceanographic Institution (WHOI) is the first to test a fundamental assumption of this ‘metabolism first’ hypothesis, and finds that it may not have been as easy as previously assumed. Instead, their findings could provide a focus for the search for life on other planets. The work is published in Proceedings of the National Academy of Science.

more…

If naturally occuring ice satisfies the definition of mineral, but not when it’s melted, then if I take whatever that we typically consider a mineral and heat it to be a liquid does that then stop being a mineral? I suppose it does.

transition said:

If naturally occuring ice satisfies the definition of mineral

It does?

>It does?

Apparently.

http://geology.com/articles/water-mineral/
To be a mineral a substance must meet five requirements:

1.naturally occurring (not made by humans) 2.inorganic (not produced by an organism) 3.solid 4.a limited range of chemical compositions 5.ordered atomic structure

inorganic (not produced by an organism)

bloody hippies. poor definition of inorganic.

http://en.wikipedia.org/wiki/Water_cluster

http://en.wikipedia.org/wiki/Water_cluster

please explain in laymans language how that relates to what we are talking about.

>please explain in laymans language how that relates to what we are talking about.

Don’t be like that. Just catch the sunday service tomorrow.

i just like pointing out crap. don’t get offended, get educated. HTH.

The general definition of a mineral encompasses the following criteria:
Naturally occurring
Stable at room temperature
Represented by a chemical formula
Usually abiogenic (not resulting from the activity of living organisms)
Ordered atomic arrangement

wiki mineral

so ice wouldn’t make it.

http://webmineral.com/Mineral_Definition.shtml

“A mineral is an element or chemical compound that is normally crystalline and that has been formed as a result of geological processes” (Nickel, E. H., 1995).

“Minerals are naturally-occurring inorganic substances with a definite and predictable chemical composition and physical properties.” (O’ Donoghue, 1990).

“A mineral is a naturally occurring homogeneous solid, inorganically formed, with a definite chemical composition and an ordered atomic arrangement” (Mason, et al, 1968).

“These… minerals …can be distinguished from one another by individual characteristics that arise directly from the kinds of atoms they contain and the arrangements these atoms make inside them” (Sinkankas, 1966).

“A mineral is a body produced by the processes of inorganic nature, having usually a definite chemical composition and, if formed under favorable conditions, a certain characteristic atomic structure which is expressed in its crystalline form and other physical properties” (Dana & Ford, 1932).

“Every distinct chemical compound occurring in inorganic nature, having a definite molecular structure or system of crystallization and well-defined physical properties, constitutes a mineral species” (Brush & Penfield, 1898).

JudgeMental said:

The general definition of a mineral encompasses the following criteria:
Naturally occurring
Stable at room temperature
Represented by a chemical formula
Usually abiogenic (not resulting from the activity of living organisms)
Ordered atomic arrangement

wiki mineral

so ice wouldn’t make it.

Classical examples of exceptions to this rule include native mercury, which crystallizes at −39°C, and water ice, which is solid only below 0°C; as these two minerals were described prior to 1959, they were grandfathered by the International Mineralogical Association (IMA).

JudgeMental said:

Usually abiogenic (not resulting from the activity of living organisms)

Surely they mean not resulting directly from the activity of living organisms. Otherwise, most minerals containing calcium (eg calcite ) wouldn’t be classed as minerals.

1959 is a tad old. definitions change. as my link shows.

I was just venturing away from water as solvent for a moment and going the other direction and wondering of that involved in mineral and compound ‘accretion’ for want of a better word, like from evaporation/drying.

and yet here…

http://www.geosci.ipfw.edu/PhysSys/Unit_3/minerals.html

who to believe?

http://www.uky.edu/KGS/rocksmn/definition.htm

Earth science (geology) definition

If you are confused about the use of the word mineral, or you are having a difficult time determining what a mineral is, you’re not alone. There are many definitions of the word “mineral.” The Glossary of Geology (Bates and Jackson, 1980, p. 401) defines a mineral as “a naturally occurring inorganic element or compound having an orderly internal structure and characteristic chemical composition, crystal form, and physical properties.” Minerals differ from rocks, which are naturally occurring solids composed of one or more minerals. Rocks do not have a distinctive chemical composition or crystal structure. The earth science definition, however, is not always used to define minerals.

we are not alone.

:-)

we could be here all night…

http://ruby.colorado.edu/~smyth/G30101.html

:-)

> All life on Earth that we have found so far lives in the temperature range of liquid water, ie zero to 100 deg centigrade. What other liquids could sustain life forms outside this temperature range? and where might these conditions be found?

Many years ago I could have given you a thorough answer to that.

My first thoughts are that this question has two quite separate parts.
1) At what temperatures could carbon-based life grow and reproduce?
2) In which liquids could carbon-based life grow and reproduce?

To give an example of why I separate this into two parts, the interiors of the planets Uranus and Neptune contain huge oceans of salty liquid water. But carbon-based life could not survive there. Why? Because it’s too hot. Temperatures in these oceans are never cooler than 2500 K. The water is still liquid because of the high pressure, but the high temperature speeds up organic chemical reactions to a rate at which the composition rapidly approaches thermodynamic equilibrium – and life requires non-equilibrium thermodynamics to survive.

On the other hand, at very low temperatures chemical reactions slow almost to a stop, and this isn’t good for growth and reproduction of carbon-based life either.

So Uranus and Neptune are too HOT for life. Pluto and its moon Charon are cooler, and may have temperatures that are perfect for the continuation of carbon-based life in their interiors, as well as plenty of water, carbon, hydrogen and other important light elements for feeding that life.

As for liquids, the most likely liquids are the most common ones, composed mostly of elements H, He, C, N, O. Other elements are always rarer. Carbon-based life needs some electrical polarisation of the host liquid, so liquid hydrogen and liquid helium are very unlikely. Liquid nitrogen, liquid oxygen, ammonia, methane, carbon dioxide, saturated hydrocarbon, benzene would need to contain some dissolved salts in order to support carbon-based life, and I’m not even sure that it’s possible then. Keep in mind that high and low pressures exist in abundance in space, nitrogen remains liquid at temperatures well above room temperature when the pressure is high enough. Methanol, ethanol, acetone, sulfuric acid, hydrochloric acid look like good possibilities at appropriate temperatures and pressures, but they’re relatively rare. I like the idea of carbon-based life surviving in lakes of large organic chemicals such as tars, asphaltenes, resins or lignins.

Damn, looks like Bubblecar is all over this as well. I might have to retire.

But yeah, to summarise:

1/ On Earth, there are things that live and reproduce at temperatures over 120 degrees C. (eg Geogemma barossii and Methanopyrus kandleri). They can temporarily survive temperatures considerably higher than that.

2/ On Earth, there are countless strains of Bacteria and Archaea that can live and reproduce at temperatures under -5 degrees C, and can survive long periods under -100 degrees C.

3/ Non-hydrous life has been theoretically mooted, including life supported by ammonia (melting point -78 C) or hydrogen fluoride (melting point -84 C).

Liquid sulfur is present on Io, and the question of whether liquid sulfur could support the growth and reproduction of life is an interesting one. Sulfur cannot be liquid at temperatures below 119 Celsius. That’s cool enough for carbon-based life. Chemicals hydrogen sulphide, carbon disulphide, oxides of sulphur may be appropriate chemicals within which carbon-based life could reproduce. I suppose I also shouldn’t rule out carbon monoxide, though that does tend to spontaneously disintegrate into carbon and carbon dioxide.

By the way, I specify “growth and reproduction” and “carbon-based life” because carbon-based life can survive in a much wider set of conditions than the conditions in which it can reproduce – such as in cold vacuum. And because life that is not carbon-based – such as computer viruses – could also reproduce and grow in a much wider set of temperatures than carbon-based life.

mollwollfumble said:

By the way, I specify “growth and reproduction” and “carbon-based life” because carbon-based life can survive in a much wider set of conditions than the conditions in which it can reproduce – such as in cold vacuum. And because life that is not carbon-based – such as computer viruses – could also reproduce and grow in a much wider set of temperatures than carbon-based life.

——

That is an interesting concept. If humans do create artificial intelligence that becomes sentient then it could survive as long as long as its circuitry survives.

While this wiki article has some issues, it does offer a reasonable discussion of alternative chemistries for life, notably alternative chirality, and non-carbon-based life.
http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry