New Mars Forums

It's OK. Eye was only kidding!
                               

rhw007 writes:-

    If you have to ask, then obviously the evidence is inconclusive, by definition.

    The next step is to ask whether it's likely Mars was warm, wet and hospitable long enough for intelligent life to develop and build towns and cities. So far, everything we know about Mars says the answer is no!
    Even the far more clement terrestrial environment, with its strong global magnetic field, dense stable atmosphere, warmer temperatures and permanent oceans, took 4.6 billion years to produce urban development!

    I suppose you could invoke travellers from another star system to explain these purportedly artificial structures, but then you're pushing speculation just as hard. Why, for instance, would these interstellar wanderers have set up home on a small, cold, dry, airless rock when they could have had Earth?

    Having said all that, someone declared the universe is not only stranger than you imagine, it's stranger than you can imagine. So I hesitate to say something is forever impossible. I even look at the Face on Mars, scratch my head and say: "I wonder ... !"

    So keep looking rhw007. The odds are massively against you but you never know ... !
                                         

Earlier in this topic (26th June '02) I wrote a summary of the discovery of a huge paleolake basin on Mars. The water from the 1400 mile long lake flowed northward through Ma'adim Vallis into Gusev crater.

    Since Gusev crater is now one of the landing sites for the Mars Exploration Rover missions, I thought it might be a good time to revisit 'Ma'adim Lake'!

    I found a high resolution picture of the lake at this site.
    The picture is an oblique view, facing south from Gusev toward the lake. They've exaggerated the vertical scale somewhat so as to emphasise the basin-like shape of the lake floor.
    The lake's surface area was equivalent to the area of Texas and New Mexico combined and its volume was equal to 5 times the total amount of water in America's Great Lakes!
    And this is no 'if-but-and-maybe' paleolake. They've found the unmistakable shoreline!

    As I've said before, what amazes me is that the surface of 'Ma'adim Lake' (as I call it) was some 1.5 kms above datum when water was overflowing from it into Ma'adim Vallis. This indicates to me that a substantial atmosphere must have existed at the time, even at that altitude.
    Mars must have an incredible history waiting to be discovered!
    We really need scientists there on the ground ... NOW!!
                                       

Many Happy Returns of the day, Robert!!
    Only another 59 years 'til you get your telegram from the Queen!
                                      :laugh:

NuclearSpace writes:-

    Does the admonishment "Don't tempt the gods" mean anything to you?!!  Keep your voice down, will ya!
                                   

I don't believe it!!!

    It looks like some half-***ed fisherman has delayed the launch of the second Mars Rover!
                                  :angry:

    Check it out at this site.

Hey, Josh ... I know it's taken me two months to realise it but I think I detect an insult!! 

    I suppose it took me this long to notice because I've been sitting here in a fog of "self-grandioseness pretending that I'm better than the rest of the world"!
                                      :laugh:

    If I appear to praise the USA too much for some tastes (and it seems any praise is unpalatable for many), it's probably only because I have lower expectations of my own species than most here seem to have.
    The fact is, I admire the high moral standards of the Josh Cryers of this world. And I was impressed by AltToWar's almost encyclopedic knowledge of every nit-picking flaw in US foreign policy and US history, which s/he demonstrated in his/her brief sojourn at New Mars. [AltToWar's appearance just before Iraq, and equally sudden disappearance afterwards, now bolsters the suspicions I aired at the time that s/he was something of a left-wing political troll .. though I could conceivably be mistaken. Nevertheless, much of what s/he said may even have been true! ]

    But my position, grandiose as it may look (! ), is simply based on the premise that it's unscientific to assume the here-and-now is special. In terms of human behaviour, I don't believe it is.
    Without wishing to labour the point incessantly, I simply say look to history. As long as there have been humans there have been wars and empires. Countries have risen to prominence, usually by tyranny of one sort or another, and then faded into relative obscurity. Violence, greed, lust-for-power and religious intolerance fill the history books from cover to cover. This is not my opinion; this is fact.

    To assume that the emergence of the UN and left-wing lobby groups, and the existence of groups of high-minded liberals (however noble and admirable), is somehow going to change all that is, to me, flying in the face of reality. To assume that the cycle of empires has ground to a halt with the arrival of America is the real "self-grandioseness" here because it tries to make the present day somehow special - which it almost certainly isn't!

    One day, perhaps sooner than we think, America will run out of steam and falter. Some people think they see clearly the beginnings of her decline right now.
    Who will fill the power vacuum? Make no mistake, somebody will ... it's a primate thing and, let's face it, we're mostly chimpanzee!
    The majority of empires have been corrupt and malevolent far beyond what the US has ever achieved in this regard. But, if you disagree, don't worry. You may live to see the Pax Americana you so despise broken forever. Then, if you watch the Disney channel a lot, you'll probably be expecting a cosy UN-administered world of peace and love!   

    Good luck!   

(P.S. You cut me to the quick with your comments, Josh! Am I to retain your respect only by agreeing with your views? That doesn't sound like the Josh we all know and love.  )

Thanks fellas!
    So many wondrous contraptions we could be using to cruise around the solar system!
    Too bad it's so hard to get past the budget committees and the environmental zealots.
                               

That was a very interesting post, Robert. You've put a lot of complicated stuff into easy-to-understand language.
    I like the sound of the 8,300 second engine. What's the best Isp figure and the best thrust for the VASIMR engine?

Josh wrote:-

    Sorry it took a while to get back to you on this, Josh. I hadn't really analysed why it tickled me.
    I'm not interested in being sexually dominated - and I honestly don't think I'm repressing any deep-seated desires in that direction which I don't consciously know about! But I understand that for various reasons some people do enjoy pain (to an extent) and humiliation - it does it for them.
    Maybe that's why there are more fantasies about nazis imposing sexual domination than liberals. The average liberal isn't renowned for imposing his/her will on anything or anybody. A nazi barks orders ... a liberal forms a committee!

    Power is sexy. Crisp military uniforms are sexy. There's something in the human psyche that just 'knows' that, however much our more rational higher brain centres tell us otherwise.
    I can't remember a woman denying she finds a man in a military uniform sexy (or at least sexier than he would be in, say, jeans and a sweater). Women used to find Henry Kissinger sexy, for God's sake! .. Because he held such power. If Bill Clinton had been the janitor at the Whitehouse instead of the President, would Monika Lewinsky have gone to so much trouble to make him happy? .. I don't think so!

    Josh, I think you've hit on something important in human thought processes here ( or perhaps a lack of thought processes! ).
    In today's modern world, women reputedly admire SNAGs (Sensitive New Age Guys). But show me two guys: One tall, dark, lean and handsome in a white naval officer's uniform, the other short, pale, fat, bald, plain and carrying a diaper bag ... and I'll show you which one will attract women! I suppose I could describe a reverse situation for men.
    Women know what they want in a lifetime partner, but it's often not what their hormones are telling them when they're shopping around.

    At some primitive level - one which has gotten the human race into some terrible trouble over the millenia - nazis are sexy and liberals are boring.
    But I hope we're not so crazy as to ever allow our fantasies to become realities again in this regard. As you probably know, I have a few problems with liberals but I have a whole helluva lot more problems with nazis!!

    Sorry to have rambled on a bit, Josh, old pal!   

Incidentally, whatever happened to Phobos and Byron? I'm really missing their comments in these pages. 

Even today, Earth bulges a little at the equator due to its rotation; its equatorial diameter is a little larger than its polar diameter.
    When the rotation period was 5 hours, I'm sure the equatorial bulge would have been very much more pronounced, as you suggest, Dickbill.
    But Earth has always been flexible due to its molten interior. Even as we speak, after a 4.5 billion year opportunity for cooling and crust thickening, Earth is susceptible to flexing. The surface of the planet itself, as well as its veneer of water, rises and falls every day in response to the Moon's gravitational pull.
    There was never any possibility of Earth retaining the large bulge which would have existed in its earliest times. Once the rate of rotation had decreased, Earth's structure was incapable of sustaining such a bulge against the pull of its own gravity.

    In the same vein, it's interesting to consider the height of Earth's tallest mountain in relation to the highest Martian peak. Mauna Kea is about 10 kms high, while Olympus Mons reaches 27 kms above datum. The ratio of the heights is almost exactly the same as the inverse ratio of the gravitational accelerations of the two planets. This suggests that perhaps each mountain is at or near the maximum height its planet's gravity will allow before the crust sags under the weight.
    One more indication that planets are more like balls of viscous liquid than solid bodies.

[ P.S. I can't remember reading anything about the Moon's original rate of rotation before it began to slow. It may be that it's impossible to know simply because its rotation is now 'captured' and we can never find out when it finally stopped spinning, from an Earthly observer's point of view. If it were still not completely 'spin-captured' today, or if we knew exactly when it became fully 'captured', I'm sure we would be able to calculate its initial rate of spin.    ]

As I understand it, a protoplanet somewhere between 1/10th and 1/5th the mass of proto-Earth struck our planet a little off-centre and at a considerable closing speed.
    The kinetic energy released on impact was enough to liquify the impactor and proto-Earth's crust. The impactor's iron core sank into proto-Earth's interior and combined with its core while some of the impact energy caused a plume of liquified and vapourised mantle/crustal material to spew out into space.
    Whatever proto-Earth's rate of rotation was before the event, we know that its rotation period (or day) after the impact was approximately 5 hours. i.e. 2.5 hours daylight and 2.5 hours darkness.
    This was soon to be modified because the ring of material orbiting quite close to what we can now call Earth proper coalesced into our satellite, the Moon. The huge tidal forces resulting from the Moon's proximity to Earth acted quickly (in geological terms) to simultaneously slow Earth's rotation and shift the Moon further and further away.
    Although a certain amount of the mixture of impactor and proto-Earth mantle/crust, which had been 'splashed' into space, would most probably have fallen back onto Earth's new surface, it would have been immediately assimilated into the roiling magma ocean.
    Any material orbiting within Earth's Roche Limit (too close to accrete into a small moon), would have formed rings. Such rings, in common with those of Saturn today, are transient things lasting 'only' some tens of millions of years at best. And we have to remember the cataclysmic impact event occurred about 4.4 billion years ago.
    In that time, our Moon has been moving steadily further away and would have 'mopped up' thousands of tiny moonlets, most quite early in the piece - contributing to its crater saturated appearance.

    I very much doubt there's still some of the original impact ejecta independently orbiting Earth somewhere. There's been ample time for the Moon to 'acquire' it or, if it were in the form of small particles, for the solar wind to dispatch it! Besides, anything substantial would have been picked up by astronomers or on radar by now.

    Ian, I've rambled on a bit here .. sorry!  Does it answer your question or have I missed the point?