New Mars Forums

Great anecdotes about German soldiers and Paris, Mundaka!
    I particularly liked your father's attitude to the jeering about his French language skills. A marvellous example to the selfish hotheads in the world of how to behave oneself and observe common courtesy, even in the face of unreasonable provocation.
   Commendable self-discipline which I admire very much!
                                             

    I found it hard to understand the behaviour of the French people baiting you, though. If I ever come across a tourist here in Australia who's having trouble with directions and/or the language, that's when I feel the most patriotic of all. I feel obliged to help them in any way I can because I'm proud of my country and I want visitors to go away with a good impression of Australians. (In addition, I guess I think of such action on my part as atonement for being so useless with 'foreign' languages when so many other people are multi-lingual! )
    Overseas visitors are guests in my country and a guest should be accorded certain civilities.
    I believe courtesy is a two-way street.
                                       

Byron writes:-

    I agree in principle with what you're expressing here. "The price of freedom is eternal vigilance" and we owe it to ourselves and future generations constantly to guard against totalitarianism.
    I made a study of nazi Germany some years ago, reading books such as "The Rise and Fall of the Third Reich" and 'Berlin Diary" by William Shirer, "Inside the Third Reich" by Albert Speer, and "Barbarossa, The Russian-German Conflict 1941-45" by Alan Clark. They proved to be quite an education not only about nazism but about the way politics works and about human nature and warfare in general.
    One of the conclusions I reached was that Hitler's rise to power was anything but inevitable. A series of highly unlikely events worked in concert over an implausible length of time to help propel a sociopath to a position of absolute power. By chance again, Hitler managed to gather to himself a small but extraordinary group of amoral and murderous henchmen.
    So many events and personalities had to mesh together at the right times that it's almost impossible to conceive of it ever happening that way again. But I do concede that a similar sequence of events in another place and time is certainly not impossible, however unlikely it may be.
    But the fact that it last occurred, to the extent that it did, in a country called Germany, doesn't convince me at all that that makes it more likely to happen in Germany again, rather than somewhere else.

    I believe each generation is its own generation and should not be held hostage by the deeds of its predecessors. While past evils should be remembered so they can be prevented from recurring, they should be seen as distinct quanta in the historical continuum, isolated and distinct and individual. The sins of the fathers should not be visited upon the sons!
    As I've said before, I don't believe in collective guilt.
                                           

Hi again, Brthrjon.
    I've been staring at that large whitish object again and I'm beginning to wonder about the apparent shadows near it. Just abutting the upper left side of the white material is a crescent of darkness which I assumed to be a shadowed depression. Now I'm wondering whether it could just be a stretch of darker sand containing more haematite(?)
    It may be harder than it looks to judge the height of things here!
    I'm afraid we'll just have to wait and see ... UNGHHH!!! ... FRUSTRATION !
                                         

Hi Brthrjon, nice to see new contributors here! (Not that there's anything wrong with the 'old' contributors, of course! )
                                         

    Thanks for bringing those whitish looking objects south-east of Opportunity to our attention. Very interesting!
    The larger whitish object, on the right, definitely looks like a prominence rather than a depression, judging by the shadows around it. And it seems to have a feint whitish circle around it like a badly eroded crater wall.
    I have no idea what the pale substance could be but it looks too bulky to be a layer of frost. If pressed for an off-the-cuff layman's opinion, I would hazard a guess at some kind of erosion resistant chemical compound - perhaps a salt or carbonate material. (Just supposition, of course.)

    If the crater indicated with the arrow is 150 metres across, the large whitish prominence must be about 350 metres across and approximately 3 kilometres from the indicated crater.
    Assuming Opportunity is actually in a crater itself, that large whitish prominence should be clearly visible when we trundle up and out onto the surrounding plain. But it may be too far for us to reach unless the solar panels stay free of dust for longer than anticipated. We live in hope!

    The black and white 3-D panorama is fascinating to look at through filters; you feel like you could just walk right into the picture!
    But the landscape beyond the low hills all around Opportunity (you can get a vague appreciation of it in sections of the panorama shot) looks like it consists of low undulating hills anyway. Is it possible Opportunity isn't in a crater at all, just a random depression in a sea of low undulating sand hills? Just a thought.

    The rock outcrop almost at the extreme right of the panorama has what looks to me to be the most obvious layered material. I can only imagine how anxious the NASA team geologists must be to get over to that stuff and have a good look at it ... I hardly know one rock from another and I'm busting my arteries with curiosity!!
                                                    :laugh:

    I can't express how happy I am with these two MER missions! What a wonderful year 2004 is.
                                                   

I don't think any seismographic experimentation has ever been done successfully on Mars to date.
    The Viking landers each carried a seismometer. Unfortunately the one on Viking I failed to send back any information, while the other one functioned for a year and only detected one seismic wave.
    Apparently this scant information was insufficient to form any hypotheses about Mars' internal structure or activity.

    I agree it would be interesting to get some marsquake data and I suppose there are people working on the idea 'as we speak'!
                                               

This is a question which has made me less optimistic about the number of 'other Earths' out there.
    That collision may well be responsible for enabling the tectonic activity which recycles CO2, preventing its complete sequestering in carbonate rocks.
    The same tectonic activity allows Earth to 'let off steam', so to speak, in a reasonably controlled manner, avoiding the kind of planetwide violent crustal upheavals which afflict Venus. It's hard to imagine terrestrial life surviving the kind of total resurfacing Venus experiences every so often.

    The collision produced the Moon, which was instrumental in slowing Earth's rotation to its present rate by tidal gravitational interactions. Calculations indicate a 5 hour day (2.5 hours daylight, 2.5 hours darkness) just after the Moon's formation but we don't know how fast Earth was rotating before the impact.
    The Moon provided us with daily tides and the intertidal zones (between the high and low tide mark) have been credited with helping life to originate (a controversial point) and, much later, with helping marine creatures to adapt to living on land.
    The Moon also stabilises Earth's axis of rotation, keeping it within a certain small range and thus preventing radical changes in our overall climate. By contrast, computer models have shown Mars' axial tilt to be prone to large and chaotic changes over geological time, varying up to 60 degrees in some simulations!

    With all the apparent benefits which ensued from that cosmic collision, and knowing that the chances of such an encounter producing just the right circumstances are probably very low, it does make you wonder whether a long-lived and diverse biosphere is actually an extremely rare thing.
    We may not be alone in the universe, but it may be a long long way between Earths! We may be living on a particularly precious jewel.
                                               ???   

I think the sheer size of the temperature differentials is important, too, in driving the winds on Mars.
    Apparently, most big dust storms originate in the southern hemisphere during summer. The southern summer happens, at the moment, to coincide with Mars' perihelion, so it's short but 'hot' compared to the northern summer which is longer but cooler.
    This kind of hemispheric difference is exacerbated by the huge day/night temperature differences, which may be as great as 110 to 120 deg.C.
    As Byron points out, temperature differences drive the winds and, on Mars ... boy do we get temperature differences!!

    The topographically driven katabatic winds on Mars have the Tharsis Bulge to help them along, too! A chilled mass of air over Tharsis, as it pours down the slopes, eastward along Mariner Valley and northward toward the lowland plains, must pick up a lot of momentum.
    And, without the heat-sink of the oceans we have here, any moderation of temperature differentials is absent.

Ha-ha!   :laugh:

    Many thanks for the kind invitation, Byron, but I'm having enough trouble getting the message through to some of the Aussies I know, never mind trying my luck in your country!
    Besides, I'm pretty sure you're doing a perfectly good job on American soil yourself, without any help from me.

    Without wishing to start a welfare debate here, I have to say I agree with you 100% that nobody who's doing O.K. financially should be entitled to social security payments. Even if, by some flaw in the rules, they are legally entitled to government money, they should have enough decency, self-discipline and pride in themselves not to accept it!!
    There was a time, not so long ago, when people who were not only legally entitled to welfare but who really needed the money, would still decline it simply out of fierce pride! Nowadays, people tend to say "Ah, what the hell .. if they're giving it out, you'd be a fool not to take it."
    I guess the world has changed.

    In any event, I'm with you. R&D and technological advancement (and big infrastructure projects) are like sowing a crop, the more you put in the bigger the harvest you reap. To me, the 'liberals' (left-wingers or whatever you want to call them) are suggesting we distribute the seed crop and eat it now! They think that's all there is. They can't visualise the wealth and plenty that will result from growing more seed!
    If we become a space-faring species, a two-planet civilisation, the phenomenal spur to technology accompanying that will create an enormous increase in total human wealth.
    Why can't some people see that?
                                         ???

Thanks, Stephen, and welcome to New Mars!

    Super oxides, super schmoxides!!!
    Never believed in 'em anyhow ... they were always a red herring to cover up for the negative results of Viking's useless Gas Chromatograph Mass Spectrometer machine, that wouldn't have picked up the existence of organic compounds in a farmyard full of horse sh**!
    Besides, the best evidence for life at the Viking landing sites was provided by Dr. Gil Levin's Labeled Release Experiment, and he was originally a sanitary engineer! How would it look if all those card-carrying members of the scientific elite who worked on Viking were upstaged in the search for life by a former sanitary engineer?!!
                                        :;):

That was a very informative post, Rob. Thanks!
                                         

    I didn't quite follow the logic of launching from as deep in Earth's gravity well as possible to get to Mars. Ideally, I'd need to see diagrams, equations and examples of calculations.
    I believe I have the first stirrings of an understanding of what you're driving at, even though it appears counter-intuitive on the surface. But it hasn't quite sunk in!
    I guess I'm a little slow at times.   

Hi again, Joe!
    Sorry I haven't come back to you in a while but there's been a lot of good stuff going on at Mars just lately!   

    It's surprising how much effect the inverse square law actually has on surface gravitational acceleration. By mass alone, you'd expect Mars to have less than 11% of Earth's gravity at the surface, but the fact that Mars' surface is nearly twice as close to its centre of gravity as Earth's surface is, you get nearly 4 times the effective gravity. In this case 0.38g.

    But getting back to the magnetic field problem, Earth has had countless magnetic pole reversals over the eons but there's no evidence of any damage to species alive here at the time of these reversals.
    This is because the magnetic field isn't that important when it comes to protection from the charged particles of the solar wind and, more importantly the very energetic solar flares which occur periodically. Our atmosphere is our protection.
    If the magnetic field were all that stood between us and the solar wind, polar explorers would be irradiated with fast-moving particles directed to the poles by the field and would die a horrible death. This doesn't happen because the atmosphere is just as thick and protective at the poles, of course, as it is at the equator. In fact, Earth's magnetic field greatly concentrates the solar wind at the poles, producing the Aurora Borealis and Aurora Australis as charged particles slam into the atmosphere at high speed, and yet it still poses no threat to a human standing at either the north or south pole.

    But the magnetic field does protect our atmosphere from the worst effects of something called 'sputtering' by the solar wind, whereby the upper atmosphere would be eroded by the incessant high speed wind of particles streaming by. This is a process which it's believed may have played a major role in stripping away the martian atmosphere over geological time, since Mars is thought to have lost its magnetic field early in its history.

    While any atmosphere we 'build' around Mars will immediately start to leak away due to Mars' lesser gravitational grip on the molecules and because of solar wind sputtering (no global field), it will take anything up to 10 million years to lose most of our new air.
    During this time, a human standing unprotected on the surface will be as safe from radiation as anyone standing here on Earth (depending to some extent on the density of that air, of course).

    I don't think atmospheric degeneration is going to be anything we'll need to worry about; we'll have millions of years to do something about it.
    I'm more concerned about creating the atmosphere in the first place!
                                             

You could set me down at either place and you wouldn't hear a single complaint!