New Mars Forums

Oops, sorry Josh!   

    I thought I was being funny ...   

Interesting comments, Byron and Cindy.

    Just to address Byron's question about circumstantial evidence, it's really just an accumulation of factors without definitive proof.
    But I believe people have been hanged on a preponderance of what was, in the final analysis, just circumstantial eveidence!
                                       

Factors:-

- Mars was probably warmer and wetter 3 to 4 billion years ago when life is known to have existed on Earth.

- Impact transfer of material, both ways, between Earth and Mars has been going on since the planets formed and is still going on today.

- Research has proved that conditions inside a substantial proportion of material transferred from Mars' surface to Earth's surface, and vice versa, never reach levels intolerable to common forms of terrestrial bacteria. Hence the transfer of viable bacteria is not only possible but the chances of it not having happened are vanishingly small.

- Bacterial life is extraordinarily adaptable and resilient, being able to evolve very quickly because of the speed of its reproduction.

- If bacteria (archaea etc.) ever existed on Mars, and through impact transfer, if nothing else, it almost certainly did, then it will still be there today in one form or another.

- Bacteria can exist in a range of environments from extreme cold to extreme heat, high salinity, high acidity or high alkalinity, or even very high radiation environments. They can exist in an oxidising or reducing environment (in oxygen or without it), flourish in and even digest toxic waste, and even survive a hard vacuum on the Moon for two years!

- Bacteria are hard to eliminate, even if you make deliberate efforts to do so. (Even Operating Rooms cannot be made entirely sterile.) If you succeed almost completely in sterilising any thing or any area, just one bacterium will totally repopulate that thing or area within a matter of weeks, given enough nutrient.

- There are almost certainly areas of Mars today which fall within the huge range of possible habitats for bacteria.

- Several unsterilised or incompletely sterilised probes have landed or crashed on the martian surface since the early 1960s.

- Although the subject for much debate, experimentation, and dispute, the Labeled Release (LR) experiments on the Viking landers gave a positive result. The damning evidence of the Gas Chromatograph Mass Spectrometer (GCMS), which found no organic material in the regolith (down to parts per billion levels), and which was used to 'prove' the LR results had to be wrong, has since been shown to be baseless. The same GCMS failed to detect the organic material in thriving colonies of bacteria in Antarctic soils here on Earth!
    [For an update on the LR results, see [http://www.newhousenews.com/archive/wylie011604.html]THIS SITE. ]

- Mars Global Surveyor photographs have shown streaks of dark material emanating from strata just below the surface of canyon and crater walls. The material is transient and the consensus is that it's probably briny water. Some have even suggested that its dark colour may be due to dormant spores of some kind of life suddenly germinating in the freshly released moisture.

- Some European scientists have examined 'dark spots' which appear and disappear in fields of frosted sand dunes and decided that their behaviour is consistent with colonies of living creatures, perhaps living in meltwater under protective sheets of ice.

    I could probably find some more circumstantial evidence, if pressed, but I hope this is sufficient to get an idea of how my mind works (or doesn't!    ) on this topic.

    Cindy, I understand your trepidation at the thought of the present United States of America being cloned and placed on Mars!
    I don't think you have to worry too much. Even if America does get there first, the ongoing colonisation would involve many countries and many cultures, including Europe, Russia, China etc. At least initially, the kind of people who grace the stage on the Jerry Springer Show (BLLECCHHH!!! ) would not be prime candidates for the trip, I suspect.
                                             

There have probably been several erosive forces at work on Mars, just as there have been here on Earth. I know there are many martian landforms consistent with extensive past glaciation, for example.
    However, I believe that many meandering valleys, with channels in their lowest sections, are difficult to explain by any agency other than the long-term slow and gentle flow of liquid water.

    Gusev crater, the current focus of attention for Mars nuts everywhere (    ) ... whoops, there's another one! ... , is only a relatively small part of a major water feature in the near-equatorial region of the southern highlands. Some of you here may recall my post of June 30th 2003 over at "Water on Mars. H2O, where'd it go?", in which I linked to a perspective view of part of a vast paleolake basin in the highlands south of Gusev(?).
    The lake, whose shoreline has been identified, had an area equal to Texas and New Mexico combined and contained 5 times as much water as the Great Lakes of North America! At its northern end, water flowed over a natural weir into Ma'adim Vallis, which is a valley feature larger than America's Grand Canyon. Ma'adim Vallis in turn, emptied into Gusev crater at its northern end, which is why so many scientists are so convinced that Spirit is now sitting on a dry lake bed.
    The natural weir between the massive lake in the highlands (I call it Lake Ma'adim) and Ma'adim Vallis sat at an altitude of at least 1.5 km above datum, yet it's believed that liquid water flowed over it for long enough to gradually erode the rock until the weir catastrophically collapsed. The contents of Lake Ma'adim surged northward along the 500 kilometre valley and into Gusev crater, which was unable to contain the thousands of cubic kilometres of water. The northern wall of the crater gave way and the waters poured out onto the northern plains, or perhaps into the Oceanus Borealis (if it ever really existed).

    One of the most interesting points about all this is the fact that liquid water flowed over that weir, at an altitude of 1500 metres (about 1 mile) above datum, for an extended period - long enough to wear away the rock. This indicates that the atmospheric pressure and the ambient temperatures, even at that height above datum, were much higher than today and remained so for a long period of time.

    The evidence, though I admit it's contradictory in some ways (see the discussions about olivine in Mariner Valley), suggests that Mars experienced relatively long periods of comparatively balmy weather, longer than the "few decades of terrestrial temperatures" which BGD mentioned.

    I think the choice of Gusev for the Spirit landing site was an excellent one. Wouldn't it be wonderful to take a shovel and dig down a metre or two?! I wouldn't be surprised if the sands are soggy with brine, even today.
                                          :;):   

    Just a few more rambling thoughts.

I have a question but, before I ask it, I'd just like to say it's good to see Nirgal 82 back on the boards ... welcome back, Matt!
    I notice that BGD is climbing into the ring a little more often lately, too. Excellent!
    By the way, Josh and Rxke, I've been meaning to thank both of you for your marathon efforts to keep the rest of us 'in the picture' with Spirit news. You, and others here, have done us proud and it's much appreciated.
                                     

    I was interested in the comments about the tiny tubes and spheres of granular material found in the martian soil. In particular, the point someone made about such structures being able to ".. withstand the region's strong winds and perpetual scouring by dust devils ...".
    It occurred to me to ask how long such structures last in Death Valley, where they're also found? Is there any indication of how durable such natural sculptures really are?

    If Gusev is constantly scoured by winds and wind-blown dust, could we expect fine crusty tubules and spherules to last, say, a year or 10 years, or a century or 1000 years?!!
    If such creations of brine evaporation are indeed fragile and short-lived in the conditions found at Gusev, could we be looking at an ongoing process of creation?
    Could these structures be relatively fresh, having been produced by recent episodes of wetting and drying of the soil? If so, perhaps it fits in with the creation of the so-called 'magic carpet' of material, which looks suspiciously like freeze-dried mud.

    Who knows, maybe much of the surface material of Mars is full of water/water-ice, undergoing repeated freezing, thawing and/or evaporation even today.
    Just a thought.
                                             

Hi Joe!
    I believe there's a fundamental error in your calculations regarding a 'bulked-up' Mars.

    You specify adding an extra 1.63 times the present Martian mass, bringing it up to 2.63 times its present figure.
    Mars is currently 0.107 times Earth's mass.
    Your new Mars would therefore be 2.63 times 0.107, or approximately 0.28 times Earth's mass.

    With a present radius of 0.53 times Earth's radius, Mars' volume as a ratio of Earth's is 0.53 cubed. In other words, Mars' volume is 0.1489 times Earth's.

    For the sake of simplicity, let's assume all the extra mass you've added is the same density as the present average martian density. Thus, adding 1.63 times the present martian mass will produce a body 2.63 times the present volume.
    The NewMars/Earth Volume Ratio will now be
                    2.63 times 0.1489, which equals 0.39

    The radius of your NewMars, will therefore be the-cube-root-of-0.39 times Earth's radius, or 0.73 of an Earth radius.

    Your NewMars will have a radius 0.73 times, and a mass 0.28 times, that of Earth.
    Therefore, its surface gravity, allowing for the inverse square law of distance, will be
                             0.28g/(0.73 times 0.73)
                             = 0.525g

    The NewMars you specify wouldn't simulate the gravity of Earth but it would produce just over half of Earth's surface gravity. I've often considered a scenario whereby proto-Mars gathered more mass during its formation, 4.5 billion years ago, and wondered what effect it might have had on the evolution of the martian environment.
    I wonder whether a Mars with a 0.5g surface gravity would look any different compared to the one we see today? Would it have held on to a denser atmosphere and remained more clement, or would we need still more gravity to make any appreciable difference?
                                          ???

Welcome Steve and Trent!
                                     
    So many new contributors here these days ... it's getting hard to keep up.

Welcome to New Mars, Baphomet!
    An informative first post ... thank you.
                                               

The language seems a little ambiguous - encouraging scientists to prepare for the mission in ten years' time.
    You could interpret that in either of two ways, but I suppose it means wait ten years, while we fool around on the Moon, and then start preparing for Mars!
                                           

    Or am I being overly pessimistic?
                                                 ???

[What am I saying?!! At least we're getting off the LEO merry-go-round!      :laugh:  ]

So! You wanna go to Mars, eh?
    Well, it looks like you'll be in very good company here, Martian Apollo!

    A warm welcome to you ... you've come to the right place.
                                               

As long as you create enclosures built to withstand the air pressure inside, you can use any design you like.
    For what it's worth, I like the idea of clear domes which go right down to ground level so you can walk up to the dome material and look out onto the rusty plains (dotted with genetically engineered plants helping to terraform our new home! ).
    Yeah, yeah ... O.K. .. so I'm a Green!!    :laugh:

    Cristoph! I'm not sure if you're aware that we've had discussions about enclosures on Mars over at "Life Support Systems", under the headings:-
  1) "Canyon habitats"
  2) "We need a brainstorming session!" and
  3) "Domed habitats".
    Your idea is unique in that it involves a geodesic dome + regolith rather than transparent material. It sounds more robust, mechanically easier to achieve, and should provide ample radiation protection, so it may become the method of choice for those reasons.
    But for me, probably because I was brought up on a diet of fictional martian cities under clear domes, I prefer the open 'feel' of such designs.
                                       

If they're going to send humans out to Mars and back, without even the benefit of a period of martian gravity on the surface, I hope they plan to use cables and rotate the ship.
    How long is the shakedown mission without a landing supposed to take?
                                           ???

Aawww!!
    I've stared and stared at the 8MB image and I can't find anything remotely resembling a skull, human or alien. I can't even find anything that looks like the 'ridge' Stu mentions ... or the shark fin, or the spear-like rock!
    I must have the wrong image, I guess.