Possilbity of past life on Mars?

[RDKirk]

A lot of evidence has piled up supporting the idea that there was water worldwide. It doesn't have to come from water itself. Geoologists found areas that clearly look like dried-up lakes, rivers, and oceans.

A few million years of light silt and sand driven by fast winds creates precisely the same patterns as water.

 

[GodLovesCats]

A few million years of light silt and sand driven by fast winds creates precisely the same patterns as water.

NASA is exploring this. But with no atnosphere anymore, where do the fast winds come from?

 

[RDKirk]

NASA is exploring this. But with no atnosphere anymore, where do the fast winds come from?

Mars has an atmosphere. A very thin one.

Actually, even Luna has an extremely then and shallow atmosphere.

 

[Ophiolite]

This is why NASA geologists are not giving up on the possibility Mars might have sedimentary rocks, fossils, or anything else showing life was previously on the planet.

Two small points: keep in mind that there are many more geologists, from around the planet than just those directly associated with NASA; secondly, we have no doubts that sedimentary rocks are present on Mars.

However, Mars has always had only 1/3 the mass of Earth to retain atmosphere, and Mars has always received only 1/4 of the solar heating of Earth to energize chemical processes, and Mars has never had a life-protecting magnetosphere of Earth.

You are equivocating a potentially life-protecting magnetosphere with no magnetosphere. That's cute, but not very helpful to a productive discussion.

Mars may have some of the most simple forms of life, but it never had enough water, heat, or atmosphere to have reached something like Earth's Cambrian period.

I would be interested in you backing that up with evidence. You are assuming that the single example we have of an evolving biosphere, Earth, is typical. You are assuming that it would take a three or four billion years to move from first life to metazoan organisms of equivalent complexity to Cambrian flora and fauna. That may be the case, but we currently lack the data to make the absolute statement quoted above.

And there was certainly not a magnetosphere comparable to the Earth's magnetosphere, which is believed created by the fusion of a Mars' sized proto-planet with the earth eons before life developed.

The Earth's magnetic field was established 3.5 billion years ago.

1. In what way do you think the Earth's magnetosphere was not comparable with that of Mars? They are thought (with a high confidence level) to have shared these characteristics:

• Initiated early in planetary history
• Existing as a self-exciting dynamo
• Generated within a convecting iron core
• Sufficiently strong to create magnetic alignments in cooling igneous rocks

2. You make contradictory statements regarding the age of Earth's field. There is good evidence for early life at 3.5 Ga, a date when, you say, the field was established. Yet you also say the field was established eons earlier. Which statement do you wish to retract.

3. Please provide a citation to support your (interesting) suggestion that the moon forming impact was responsible for the initiation of the Earth's field. (Interesting, since it introduces your third date for the field's origin and interesting since I do not recall the research that suggested this. )

Mars could never have been like Earth.
But then, "Earth-like" has become a very loose characteristic in some astronomy circles...primarily to gain public attention.

Mars was like the Earth in the following respects (there are others) :

• Formation through accretion processes in the solar nebula
• Broadly similar elemental composition
• Differentiation into crust, mantle and core
• Volcanic activity producing extensive basaltic flows
• Possible (early and brief) plate tectonics phase
• Weathering and erosion producing numerous comparable landforms

I challenge your claim about the loose use of the phrase "Earth like", unless you restrict it to popular science accounts. In each instance that I have seen the phrase used in research articles its meaning has been explicitly defined, or implicitly defined by context. Feel free to present counter examples.

There were not even solid rocks during the Hadean phase.

Incorrect. The Hadean extended from the origin of the Earth to 4.0 Ga. You claim there were no solid rocks throughout this time. However, age dating and isotope analysis of zircon crystals from Jack Hills in Australia and other locations, demonstrates that crustal rocks existed within the Hadean.

The Earth's magnetic field was established 3.5 billion years ago. The solar wind flux at that time was about 100 times the value of the modern Sun, so the presence of the magnetic field helped prevent the planet's atmosphere from being stripped away, which is what probably happened to the atmosphere of Mars. However, the field strength was lower than at present and the magnetosphere was about half the modern radius.

There was no life possible in this region of the Solar System during the period that Mars had an effective magnetosphere.

Citations requested for the emboldened assertions.

A few million years of light silt and sand driven by fast winds creates precisely the same patterns as water.

Citations requested that justify this absolute statement. Alternatively, acknowledge that "A few million years of light silt and sand driven by fast winds might create similar patterns as water," is a more accurate statement.

 

[Halbhh]

NASA now has evidence and proof Mars is not completely dry and in fact used to have a lot more liquid water than it does now. How do they know? By actually finding such water on the planet, as well as ice in what looks like a mostly dried up lake. At least one river has been found. Even an underground lake was discovered years later. This is why NASA geologists are not giving up on the possibility Mars might have sedimentary rocks, fossils, or anything else showing life was previously on the planet. What do you think?

I speculate a lot of planets may have had some elementary life arise, and then in typical situations in typical planets that would soon enough end up with that elementary life becoming extinct due to normal physics as is commonplace in normal solar systems. For instance, a planet even around a very stable star like ours would gradually loose it's surface water, naturally, due to just typical solar wind alone, over time, unless the planet has an usually strong magnetic field. (ask if you are interested in articles on this ) Other typical mechanisms for extinction we now have learned are commonplace would include the natural migration of planets that would usually happen unless/until a fortunate stable system emerges, which only happens after a lot of planets are ejected, merged or absorbed into the star. Another typical mechanism that would naturally cause early sterilization of a planet are impacts by typical large asteroids, which only a nearby gas giant (like our own Jupiter) would tend to reduce, but a nearby gas giant tends to normally cause gradual migration of orbit for small planets -- unless there is an uncommon natural canceling of resonances due to other gas giants, as we have in our system -- thus normally and eventually freezing or boiling their water, likely ceasing any biological activity on most on them.

 

[GodLovesCats]

Halbihh:

It is interesting that you call Jupiter "nearby." Venus is the closest gas planet to Earth.

The International Astronomy Union changed Pluto's status as a planet partly because its orbit is not really a separate orbit as it spends part of the year in front of Neptune. The other reason is its size, so the IAU's categorical name is dwarf planet. (This definition makes Mercury the minimum size to be a planet.)

I also want to see links to legitimate citations, but you overestimated how long ago Earth's tectonic plates drifted apart. The reason dinosaur bones have been found on several continents is they lived on Pangea - the "supercontinent" that was most of Earth's land mass during the early Triasstic period.

 

[Halbhh]

Halbihh:

It is interesting that you call Jupiter "nearby." Venus is the closest gas planet to Earth.

The International Astronomy Union changed Pluto's status as a planet partly because its orbit is not really a separate orbit as it spends part of the year in front of Neptune. The other reason is its size, so the IAU's categorical name is dwarf planet. (This definition makes Mercury the minimum size to be a planet.)

I also want to see links to legitimate citations, but you overestimated how long ago Earth's tectonic plates drifted apart. The reason dinosaur bones have been found on several continents is they lived on Pangea - the "supercontinent" that was most of Earth's land mass during the early Triasstic period.

Well, I'm aware of the distances to planets (astronomy is a very old and life long interest of mine, and I'm sort of a storage bin of a huge number of facts and information from the field, if you like). Jupiter is close enough both to deflect many dangerous comets and asteroids that might otherwise bombard us even today, and also it's close enough to migrate Earth out of it's current orbit in a deadly way...except that will not happen due to the cancelling effects of the other gas giants, in our very fortunate configuration we have. Would you like articles to read on any of it -- please ask about a specific thing, since there are actually like 10-20 aspects that matter. I wasn't discussing dinosaurs of course in that post, but only the most elementary life forms at all, the early forms that at least on Earth accounted for vast stretches of time before more advanced forms evolved. Continental drift and volcanism are thought to have been very helpful to life as we know it here though, by the way.

Here's one about how we are fortunate (or by providence of course) have these protecting gas giants:
Life on Earth Can Thank Its Lucky Stars for Jupiter and Saturn | Space

 

[GodLovesCats]

I knew you were not talking about dinosaurs. I was just saying the continental drift happened much later. The timing is proven by where fossils of animals that lived during the Triassic period were discovered.

Your avatar is a giveaway you love astronomy. Is it the Milky Way?

 

[expos4ever]

And, for that matter, moving and living in the most remote, hostile regions of Earth would be easier than colonizing any other planet.

New Jersey?

 

[Gregory95]

Clarification please

Do you believe in aliens ie non humans from other planets?

 

[GodLovesCats]

Clarification pleas.

Do you believe in aliens ie non-humans from other planets?

The word alien has nothing to do with outer space. It means anyone who is in a foreign land. When I was in Europe, I was an alien to Europeans. So yes, I believe in aliens, because the word describes all people. (Look it up in the dictionary if you don't believe me. This is the English definition.)

With that out of the way, the answer to your question is no. Nothing has ever been brought back from an extraterrestial planet (which could only be Mars) and found to have organic material. What I believe is Mars certainly could have at one time been able to support life, but can't do so anymore.

 

[Gregory95]

I understand what alien means im simply trying to get clarification

Do you believe NASA model of the universe that its unlimited if so

Do you believe there is intelligent life besides us?

The word alien has nothing to do with outer space. It means anyone who is in a foreign land. When I was in Europe, I was an alien to Europeans. So yes, I believe in aliens, because the word describes all people. (Look it up in the dictionary if you don't believe me. This is the English definition.)

With that out of the way, the answer to your question is no. Nothing has ever been brought back from an extraterrestial planet (which could only be Mars) and found to have organic material. What I believe is Mars certainly could have at one time been able to support life, but can't do so anymore.

 

[Ophiolite]

The word alien has nothing to do with outer space. It means anyone who is in a foreign land. When I was in Europe, I was an alien to Europeans. So yes, I believe in aliens, because the word describes all people. (Look it up in the dictionary if you don't believe me. This is the English definition.)

With that out of the way, the answer to your question is no. Nothing has ever been brought back from an extraterrestial planet (which could only be Mars) and found to have organic material. What I believe is Mars certainly could have at one time been able to support life, but can't do so anymore.

Please excuse a couple of pedantic corrections.

Like many words in the English language alien has a variety of meanings, often dependent on context. Alien life will generally be understood to refer to any lifeform not on, or originating from Earth. When exobiologists talk of alien life they are most often thinking of primitive lifeforms, akin to bacteria, rather than little green men. If I see aliens written on a conspiracy forum it is almost certainly referring to the aforementioned green fellows. So, you are incorrect to say that alien has nothing to do with outer space. (And you need to recheck your dictionary, or buy a new one. )

Now, as to organic material: some members of the SNC group of meteorites, which are known to have come from Mars, do contain organic material. See for example this. Organic material has also been detected in several other meteorites, on comet, in interstellar space and in interstellar gas clouds. The last time I checked more than one hundred different organic molecules had been detected. Keep in mind that organic and biological are not equivalent in this context. Organic material is simply material that contains carbon atoms.

 

[Astrophile]

It is interesting that you call Jupiter "nearby." Venus is the closest gas planet to Earth.

Venus is one of the terrestrial planets; it is not a 'gas planet'. It has a very dense, cloudy atmosphere that conceals the surface from view, but the solid planet constitutes 99.99% of the mass of Venus and it has essentially the same structure as the Earth, with a silicate mantle and a nickel-iron core.

The International Astronomy Union changed Pluto's status as a planet partly because its orbit is not really a separate orbit as it spends part of the year in front of Neptune. The other reason is its size, so the IAU's categorical name is dwarf planet. (This definition makes Mercury the minimum size to be a planet.)

The IAU changed the status of Pluto because it has not cleared its orbit of other bodies of similar size, not because its orbit overlaps with that of Neptune.

The criterion for a true planet is that it has cleared its orbital space of other bodies, not its size. A body that was smaller than Mercury but still large enough to be spherical, and that had cleared its orbital space, would be classified as a true planet. Since Pluto is large enough to be spherical, it is classified as a dwarf planet rather than as a solar system small body.

 

[GodLovesCats]

What do you mean by clearing its orbital space?

 

[Astrophile]

With that out of the way, the answer to your question is no. Nothing has ever been brought back from an extraterrestrial planet (which could only be Mars) and found to have organic material. What I believe is Mars certainly could have at one time been able to support life, but can't do so anymore.

According to List of Martian meteorites - Wikipedia , small amounts of organic compounds have been found in the Martian meteorites Allan Hills (ALH) 77005, ALH 84001, Nakhla, and possibly Yamato 000593. Also, carbonaceous meteorites, which come from asteroids rather than planets, are rich in organic compounds. I am using the word 'organic' in its chemical sense, referring to the chemistry of carbon compounds, with no necessary implication of biological origin.

 

[Astrophile]

What do you mean by clearing its orbital space?

According to Clearing the neighbourhood - Wikipedia , 'In the end stages of planet formation, a planet ... will have "cleared the neighbourhood" of its own orbital zone, meaning it has become gravitationally dominant, and there are no other bodies of comparable size other than its natural satellites or those otherwise under its gravitational influence. A large body that meets the other criteria for a planet but has not cleared its neighbourhood is classified as a dwarf planet. This includes Pluto, which is constrained in its orbit by the gravity of Neptune and shares its orbital neighbourhood with many Kuiper belt objects.'

The website gives three mathematical criteria for 'clearing the neighbourhood'; all of these clearly discriminate between true planets and dwarf planets.

 

[Nithavela]

Considering the state of Mars, I think there's a real chance that they had life, but sadly it invented capitalism.

 

[ViaCrucis]

I knew you were not talking about dinosaurs. I was just saying the continental drift happened much later. The timing is proven by where fossils of animals that lived during the Triassic period were discovered.

Your avatar is a giveaway you love astronomy. Is it the Milky Way?

Just to make sure it's clear, the earth has always had continental drift. Since the earth has a molten mantle then the plates, comprising the crust, are in constant motion. Moving apart, moving into, subducting, etc. This has been going on since the cooling of the crust during the Hadean eon.

-CryptoLutheran

 

[GodLovesCats]

Just to make sure it's clear, the earth has always had continental drift. Since the earth has a molten mantle then the plates, comprising the crust, are in constant motion. Moving apart, moving into, subducting, etc. This has been going on since the cooling of the crust during the Hadean eon.

I don't recall saying Earth never had a continental drift before the creation of Pangea. However, it is clear in Genesis 1 God gathered the waters together to create one huge ocean. So at some point the Earth had multiple continents prior to Pangea; then they combined to become one except for most of Antartica.