New Mars Forums

I'm with you, Rxke!
    I love New Mars too and have formed cyber friendships with many humorous, intelligent and enthusiastic people through these posts.
    And your input here in recent months has been a shot-in-the-arm for this board as well, at least for me! [Occasionally I do get a little 'down' about space exploration, especially in the face of articles like the one Cindy linked for us, written by a cheerful soul called Stephen Strauss and describing Mars as the "De*** Pl****"!! (Sorry, not allowed to mention the actual words used. Cindy has quite correctly indicated we DON'T want that little two-word catch phrase infiltrating anyone's thought processes! ). But bright and penetrating posts from the likes of you certainly do add zest to my day!]

    I think what you've said to Stu about his activities probably speaks for the rest of us, too. I've always admired the 'doers' in this world; the ones who actually put in some sweat and some time, not just words.
    Stu is indeed a gifted communicator and his energy and drive, combined with that obviously deep-seated love for his chosen subject(s), make him a formidable weapon in the struggle "against apathy and ignorance", as he puts it.
    Go Stu!!!!
                                 

    While I'm at it, kudos to Josh, too, for his stalwart refusal to give up on Beagle 2. I admire stoic tenacity in people and, although everyone here knows poor Josh's political education is sorely lacking in several areas, you can't fault him for tenacity!!
    Jus' foolin' witcha, bro'!   
    I've got all my fingers crossed for that courageous little probe, too.

    As for the 'crunch' under my boot on Mars, Cindy, you may be reading a little too much into the word. What was going through my mind when I wrote it wasn't so much snow as a mixture of sand, ice crystals and duricrust. Stu's evocative use of the word "brittle" set the scene in my mind (he paints a vivid word picture, that guy! ) and I just extrapolated from there to the possible sound of a boot on a searingly cold mix of ice and sand.
    I've never experienced the sound of snow in temperatures as low as 0 deg.F. (Brrr!! ) One night in London, while temperatures further north in the Midlands dropped to -28 deg.C (which I think was a record low at the time? ), the thermometer got down to -12 deg.C. That was the coldest night I've ever known but there was no fresh snow to walk in.
    I am familiar with the 'CRUMPing' sound of walking in thick snow, as described by Stu, though.
    But where I live now, just 16 deg. south of the equator on the coast of the Coral Sea, there certainly ain't no such animal as snow! We don't even get close to a frost on a starry winter night. But sometimes on a sticky hot summer afternoon, when there's hardly a breath of wind, and the air's so thick and warm and wet you feel you're drinking it instead of breathing it, you get to yearning for some of that crisp cold weather.
    That's humans for you ... never satisfied with anything!
                                                 :laugh:

Well Mark, I think:-
a) The scientists at NASA would be hopping up and down yelling for sample return missions.
b) The pork-barreling U.S. congressmen/women would ignore the whole thing and keep calling for a new OSP.
c) The creationists in positions of authority in America would either go into denial-mode or contrive to find a passage in the Old Testament which specifically mentions bacteria on Titan and alien fish in the Europan ocean!!!

d) I should stop being so cynical and paranoid.
                                             :laugh:

I don't see why your scheme wouldn't work, Bill. And I think people would be surprised by the number of volunteers you'd get for the (one-way) trip.
                                         

    Whichever way you look at it, it's a far more comprehensive and detailed plan for the human settlement of Mars than anything we have at the moment!
                                           

That was a beautiful description of the martian night sky, Stu. It felt like I was there and I swear I felt a shiver run up my spine as the intense cold seeped through my suit insulation!
    " .. brittle martian air... "  I love it! I can almost hear the muffled crunch of frosty sand under my boot.

    My hands are up so high I almost dislocated my shoulders!
                                                  

It's always nice to be appreciated, Cindy! But that explanation was rather perfunctory and scrappy due to time restrictions. I now have a little more time available and would like to attempt a better explanation, as much for completeness in my own mind as anything else (just humour me and keep smiling! ). It is quite a fascinating situation on Mercury, after all.
                                     

    In order to get a grip on what's happening, let's separate Mercury's rotation from its orbital revolution.
    Let's start by supposing that Mercury has no sidereal rotation at all. In other words, no matter where Mercury is in its orbit about the Sun, the same stars sit motionless above your head as you stand on the equator. But Mercury is still orbiting the Sun, anticlockwise as seen from above the Sun's north pole, once every 88 days (Earth days).
    If you imagine yourself standing on the equator at noon facing due north (carrying a parasol and wearing 15,000+ sun-block!! ), as time passes you would notice the Sun moving slowly toward the eastern horizon. In fact, after 22 days, or 1/4 of a Mercurian year, you would notice the Sun setting on the eastern horizon, having moved 90 degrees from the zenith. Remember, none of this movement is due to any rotation of the planet; it's all due simply to its revolution around the Sun.

    But now, let's stop Mercury revolving around the Sun! Let's imagine we can persuade it it to remain motionless in space relative to the Sun without falling into the nuclear fires.  And let's now re-introduce Mercury's slow west-to-east rotation, which turns it 360 degrees every 58.646225 days (Earth days again).
    Let's start at the same point we did before. In the same 22 days you've been standing on the equator facing north, Mercury's W-to-E rotation would appear to make the Sun move 22/58.646225 times 360 degrees to the west, as it's supposed to do on any self-respecting planet! i.e. 135 degrees to the west.

    So, in the same 22 day period, we have Mercury's revolution around the Sun trying to cause the Sun to move 90 degrees to the east, while Mercury's rotation is trying to cause it to move 135 degrees to the west! Which movement wins? Obviously, the larger westward movement predominates.
    The overall effect is to cause you, still standing on the equator facing north(! ), to see a net movement of the Sun 45 degrees (135 - 90) to the west.
    This 45 degree westward motion of the Sun in the Mercurian sky has occurred during 22 days, which is 1/4 of a Mercurian year of 88 days. So, over a full year, the Sun would move westward by 4 times 45 degrees, or 180 degrees. This places it on the other side of Mercury, directly beneath your feet; in other words, you'll now be standing on the equator at midnight, wishing you'd brought thermal underwear with you!
    If you stay put for another 88 days, you'll notice the Sun has now returned to its original position directly overhead, a total of 176 days after you began your lonely and uncomfortable vigil.

    So noon to noon (or dawn to dawn, or dusk to dusk) on Mercury is a period of 176 days, which is exactly 2 Mercurian years.
    A very peculiar situation, but there it is!   

    [And there are other anomalies to the Sun's apparent movement on Mercury, too, which relate to its marked orbital eccentricity. This eccentricity causes Mercury to move much faster at certain times in its orbit and leads to 'double dawns' and 'double sunsets' on occasions. In other words, the Sun can set, then appear to rise above the horizon again before finally sinking out of sight. And it can do the opposite at dawn; appearing, dropping back, then rising once more above the horizon.
    But that's a whole different ball game and I'm not even going to try to explain that one!!]
                                                         :laugh:

Hi Cindy!
    Just popped in to attempt a quick explanation of something which takes a little bit of chewing over to really understand.
    Mercury is gravitationally locked into a rotational ratio whereby it rotates three times on its axis for every two revolutions around the Sun. This a stable tidal relationship in the same way that the one-to-one ratio of our Moon's rotation and revolution about Earth is stable.
    This is why sunrise to sunrise, at the same spot on Mercury's surface, takes exactly the same time as two Mercurian years.

    This peculiar anomaly is difficult to understand from our terrestrial perspective because Earth rotates hundreds of times for each revolution around the Sun, whereas Mercury's 'day' and its year are much closer to the same duration.
    The mechanics of it may be easier to grasp if you consider what has been mentioned here already. Our Earthly day is 24 hours long from noon to noon, but only 23 hours and 56 minutes long from 'celestial noon' to celestial noon' - not much difference because Earth's rotation rate is so high. But it takes Mercury so long to rotate once on its axis that a significant proportion of its year (2/3rds) passes in the same period of time.
    Get a tennis ball and move it around a light source twice, while rotating it exactly three times. If you do it right, you should see why there are two Mercurian years between sunrises!

    It is quite difficult to conceptualise, I admit, but I hope that helps!
                                     

As far as I know, the surface pressure on Titan is about 1.5 bar and a human should have no trouble breathing air at that pressure.
    From memory, I believe Titan's gravitational acceleration is only 1/7th that of Earth. If Titan were closer to the Sun and therefore warmer, it wouldn't be able to hang on to all that 'air'. The molecules of its gases would be moving much faster and would achieve escape velocity and/or be sputtered away by the solar wind.

    But, in theory, I suppose a human rugged up in thermal underwear and wearing a heated respirator could wander around on the Titanian surface without a pressure suit. But in fact, any exposed skin would freeze very quickly in the ambient temperatures of roughly -200 deg.C and I think there are some exotic and toxic gases mixed in with the atmospheric nitrogen, too. Maybe some of those would absorb through exposed skin and cause problems even if the intense cold didn't getcha!!
                                                 :laugh:

Mark:-

    Is it immoral to wish your life away?!
                                                

Sorry Cindy!
    I've been less than clear in my explanation of the bit about Mars becoming a lifeboat for humanity.
                                         
    The part about Mars wasn't included in the New Scientist article; I read it on some obscure google site quite some time ago. (In retrospect, I can see that it would be easy to assume that factor came from the same article .. my apologies.)
    As far as where it fits in with Dr. Kargel's timetable of future events is concerned, I would be inclined to place it somewhere between the formation of Pangaea Ultima and the great dying of 95% of terrestrial plant life in 500 million years.
    Let's say that Earth is becoming very uncomfortable in about 400 million years. (Most of our plant life is still hanging on but the average daily temperature in Chicago in winter is about 40 deg.C!! i.e. 104 deg.F, with humidity constantly near 100% .. Don't even ask what summer in Florida is like! )
    At that point, as I understand it, Mars would still be colder than Earth is now, on average. And as the Sun gradually heats up, Mars would become more and more pleasant and become a balmy 'new Earth' for maybe 400 to 500 million years - until New Chicago in Cydonia gets just as bad as old Chicago in Illinois became!!   
    All this would take place while old Sol is still a main sequence star, long before the expansion into a red giant.

    Admittedly, all this is unlikely to bother us as a species, since most species don't survive in the same form for much more than an average of 4 million years. And, even if we are there for the 'big BBQ', as Byron points out we'll have technology beyond our wildest dreams today and should be able to survive the red giant phase our Sun will go through.
    If the manipulation of planetary orbits is routine by then, we could even wait out the red giant phase, avoid the out-puffing of stellar material as the Sun shrinks down to a white dwarf cinder, and manoeuvre our chosen planet into a close orbit around the ember of our once glorious star.
    A white dwarf star can go on radiating for hundreds of billions of years, much longer than its main sequence life span. As long as we're close in, we could keep comfortably warm for a very long time.
    When I said "our chosen planet" I meant that we might need something other than Earth, which by that time would have become geothermally dead. With no volcanism for mountain building, all the continents would have eroded into the seas and we'd live on a water world with no land masses. Without the volcanically-driven recycling of carbonate rocks to create CO2 in the atmosphere, we'd have trouble maintaining plant life too.
    I don't know where we'd get a 'fresher' planet to live on but I think we might need one!

    But, as Cindy says, galactic collisions and other long-term events will have had time to overtake us by then and we may have bigger problems to overcome than trivial things like moving planets around solar systems!!      :laugh:

    As for intergalactic migration, who knows? With the 'technology of the gods' in our hands, we may be able to circumvent Relativity with ease and travel the universe at will.

Rxke:-

    You said it, pal!!
    2004 has the potential to be a champagne year for space cadets. There's Mars Express (and Beagle 2 ?), the two MERs, and the arrival of Cassini and Huygens at Saturn.

    Yeeehaaaawww!!! Now that's what I call a year to remember ... we hope!
                                      :;):   

Hi Stu!
    I admire your well justified optimism at this stage of the search for Beagle 2; you're quite right in saying the game isn't over yet.
    If we ever get around to going to Mars, though, I feel reasonably confident that an attempt at terraforming will take place sooner than "many hundreds of years, if ever". The development of domed-over-crater cities on the Moon, on the other hand, I have trouble visualising. Here at New Mars, we've gone into the basic technical requirements of creating domes over cities on Mars, an essentially similar task to domes on Luna, and the problems of containing the awesome upward forces on the domes themselves demand extreme engineering solutions.
    On Mars, rich in all the minerals needed by modern industry and rich in water and other volatiles, where humans could live and work, the incentive to achieve such demanding technological feats would be enough to ensure they are attempted. On our desolate Moon, devoid of volatiles, completely lacking an atmosphere, and with its enervatingly low gravity, I have the most serious doubts that anyone will ever live there for more than a few months at a time, nor ever want to! Large settlements seem to me to be not only unlikely but also unnecessary. Small scientific outposts or mining colonies are probably all that will ever be built there, unless a low-gravity playground for wealthy tourists is added to the list.

    Domes may well be the first stage of Mars colonisation but, soon after the first domes are constructed, the impetus toward terraforming will be irresistible. Even if the atmosphere could be thickened up to about 350 millibars of CO2, that at least would allow the domes thereafter to be made very much bigger because the enormous pressure differential problem across the dome material would be eliminated.

    This may sound like sacrilege but the possible loss of Beagle 2's life-seeking experiments doesn't really trouble me greatly. To my mind, the likelihood of DNA-based life (i.e. the same basic plan as terrestrial life) being found on Mars is very high; in fact, I'd be simply amazed if it proved not to be the case. For me at least, Beagle 2 might raise the probability from 99.5% to 100%!
    While it would be nice to know for absolute certain that there are microbes on Mars, it would hardly be Earth-shaking news for me. But the consequences for future crewed missions could be rather less rosy than you outline in your post. As soon as Beagle 2 or some such craft discovers irrefutable proof of biological activity in the martian soil, there'll be the predictable flurry of demands that a sample is returned to a secure quarantine facility on Earth, or in Earth orbit, for detailed analysis. All the usual concerns will be raised by the usual suspects about man-eating pathogens eating our astronauts alive on Mars or, worse, coming home with them at the end of the mission to eat all of us here at home!
    The other side of the coin will be the reaction of the anti-technology 'bug-hugging greenies' (a la NovaMarsollia), who'll start on about the evils of imposing our imperialistic will on the fragile martian ecosystem.
    All of these people seem oblivious to the fact that life has been hitch-hiking both ways between Mars and Earth for as long as the solar system has existed, and that various contaminated probes from Earth have crashed onto Mars periodically since the 1960s!
    The prospect of damaging bio-transfer in either direction is thus vanishingly small - essentially zero - but we'll still be required to take elaborate precautions costing billions and lasting decades, before we can send a human to explore Mars. Send me on Mars Direct! Let me be your guinea pig. I have absolutely no fear whatsoever of martian germs because they'll be the same familiar germs I left behind on Earth. Even if I'm wrong (zero chance, in my view), I'll have over 500 days to develop the symptoms of Martian Myopia or Red-Planet-Rubella and drop dead. The perfect quarantine period, 500 days and 100 million kilometres from the rest of humanity!
    Ask any astronaut and I practically guarantee you s/he'll say the same thing: "Where do I sign up for the first trip?!"

    No, for now it's probably better we should go on thinking Mars is sterile and coated in weird and wonderful superoxides. Nevertheless, a part of me still wants Beagle 2 to phone home!
                                          :;):

I'm with Dr. Zubrin!
     Much as I think further exploration of the Moon and the establishment of a permanent base there are very worthwhile projects, if it's all to become just a multi-decade, pork-barreling militarisation of cis-lunar space, then I oppose it.
    The astronauts who advocate a return to the Moon are being naive if they imagine that such activities will be a test-bed for technology which will help take us to Mars. Although that certainly could be the case, it seems much more likely to me that it'll end up a black-hole for tax-payers' money and will delay the much more important exploration of Mars indefinitely.
    The astronauts, like Jim Lovell, who want us to go back to the Moon are not stupid people; they can surely justify their opinions with logical and sensible arguments. But I fear these logical high-achieving individuals don't fully realise what they're dealing with ... politicians and the general public!
    If President Bush's administration were to announce a return to Luna in a conservative, measured, carefully staged scheme lasting 20+ years, with the possibility of using the experience gained there to fly to Mars some time maybe 30 years from now, it would be a disaster. The Moon is potentially just another arena for the military to find excuses to spend enormous amounts of money because 'the Yellow Peril is coming". And all this talk about mining Helium-3 and sending it to Earth to power fusion reactors is the most incredible nonsense and yet it gets trotted out for an airing almost every time the Moon is mentioned. In "Entering Space", Bob Zubrin calculates that in order to get 1kg of Helium-3, you would need to strip mine and process 250,000 tonnes of lunar regolith ( i.e. you'd have to scrape up the top 10 cms of dirt over an area 1000m by 1000m ). This represents a huge mining operation, which is patently unlikely to become feasible for several decades. It also ignores the small problem that we've yet to achieve practical energy production from nuclear fusion and probably won't for at least 20 to 30 years.
    Dr. Zubrin goes on to say that you don't go after Helium-3 first and hope a space-faring society will spring from it; you create a Type II space-faring society first and then resources like lunar Helium-3 become available to you.
    As for building a radio telescope on the far side of the Moon, that is a noble goal and I agree with it wholeheartedly. But again, such a project will take a geat deal of money and political will over a lengthy period and will appeal to scientists, but not the general public.

    The Moon will be seen as a 'been-there-done-that' drag for most of humanity and they're most unlikely to maintain any enthusiasm for the idea at all, assuming they can muster any in the first place!
    Mars has mystique and a certain visceral allure to go with its natural resources and potential habitability. Not only is it scientifically far more attractive than Luna could ever be, it is politically a far easier sell than a ho-hum return to our dry, desolate rock pile of a satellite.

    The Moon is a dangerous side-show which will eat money for years and achieve little else. Mars is the main event and we don't need the Moon to get there.

[My two cents worth!     ]