June 12 2007 Icy Moons (rev 46) |
June 12 2007 Icy Moons (rev 46) |
Jun 14 2007, 07:15 AM
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#31
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
I dunno -- it seems to me that to move across the surface of a small body which has such little mass that it's truly what I would call a microgravity environment, you can't rely on the possibility that you will encounter a natural handhold when you need to slow down, stop, or change directions. Grab hold of a rock sitting on the surface, and you're not going to stop yourself, you're going to pull the rock off of the body and bring it with you.
I think you'd have to somehow implant anchoring stakes on such a surface and string lines between the stakes. The stakes would have to be driven deeply enough to be able to stay anchored as the mass of your body, plus your environment suit, pulls at them with the force of your momentum. So it looks like small bodies may have to be "prepared" for human exploration before anyone can actually touch them and maneuver around on them. This wouldn't just apply to small icy bodies like Atlas, but to most small bodies like asteroids and comets. You'd have to pre-emplace anchors and lines in order to safely move around the surfaces of such bodies. Otherwise, you'd either fly right off (though I imagine you'd be tethered to your ship) or you wouldn't be able to easily maneuver to the location on the surface you want to visit. Your other option, of course, would be to use something like the AMU, a self-contained, RCS-controlled backpack that would move you along the surface and automatically adjust for the tiny pull of the body you're studying. It would be more like flying along, facing an icy or rocky wall, than "walking" on the body. -the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Jun 14 2007, 07:50 AM
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#32
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SewingMachine Group: Members Posts: 316 Joined: 27-September 05 From: Seattle Member No.: 510 |
You reach out in front of you to a small encrusted projection, barely a minor ridge within your formerly terrestrial frame of reference but a mountain here...and you pull on it as if you were diving along a coral reef...and you move with surprising velocity over the snowy surface, at an altitude of centimeters, looking for the next ridge to shove you ever onward... Blissful. A deep dream come alive. Float almost effortlessly across a surface, and scoop a handful of the rings of Saturn as you pass by, glance up and see Saturn huge in front of you, the major moons as bright stars or perhaps barely resolvable tiny crescents if you're particularly lucky...who could want anything more? Toyota (smack) That's nifty, nprev. I want a picture of this. -------------------- ...if you don't like my melody, i'll sing it in a major key, i'll sing it very happily. heavens! everybody's all aboard? let's take it back to that minor chord...
Exploitcorporations on Flickr (in progress) : https://www.flickr.com/photos/135024395@N07/ |
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Jun 14 2007, 11:42 AM
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#33
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Member Group: Members Posts: 813 Joined: 29-December 05 From: NE Oh, USA Member No.: 627 |
Gotta add: "skimming". Let's say, and why not, that you're in a spacesuit on the surface of this moon with which you have barely any gravitational connection. You reach out in front of you to a small encrusted projection, barely a minor ridge within your formerly terrestrial frame of reference but a mountain here...and you pull on it as if you were diving along a coral reef...and you move with surprising velocity over the snowy surface, at an altitude of centimeters, looking for the next ridge to shove you ever onward... Blissful. A deep dream come alive. Float almost effortlessly across a surface, and scoop a handful of the rings of Saturn as you pass by, glance up and see Saturn huge in front of you, the major moons as bright stars or perhaps barely resolvable tiny crescents if you're particularly lucky...who could want anything more? Very nice nprev.... you expressed exactly what I felt and saw in my minds eye. Thanks Stu for the term "golluming"... And dvandorn is correct that moving along the surface of small bodies will be quite a challenge. Which is EXACTLY why it will someday be done and built its own ethic, technique, and terms.... fun to think about. But for now I will just delight in nprev's words and my mental play... Craig |
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Jun 14 2007, 06:14 PM
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#34
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Member Group: Members Posts: 655 Joined: 22-January 06 Member No.: 655 |
I reckon that Pan and Daphnis may look pretty similar in close-up, with Pan (based on far-out images so far) being an even more extreme case than Atlas with the whole snow-girdle thing.
I'm going to show my ignorance here, but presumably Atlas is not tidally-locked to Saturn, leading to roughly equal accretion of ring particles around the equator, rather than them piling-up preferentially on the leading hemisphere. If not tidally locked, then it lends wait to the theory of the rings (and embedded moons) being the result of the disruption of a body that wandered too close to Saturn, and that the rings themselves are a (cosmologically) fleeting phenomenon that we're very privileged to see. |
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Jun 14 2007, 06:51 PM
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#35
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Senior Member Group: Moderator Posts: 3234 Joined: 11-February 04 From: Tucson, AZ Member No.: 23 |
Actually, Pan is lemon-shaped.
-------------------- &@^^!% Jim! I'm a geologist, not a physicist!
The Gish Bar Times - A Blog all about Jupiter's Moon Io |
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Guest_AlexBlackwell_* |
Jun 14 2007, 06:53 PM
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#36
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Guests |
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Jun 14 2007, 08:00 PM
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#37
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
Just wondering... does anybody else live in a constant sense of amazement at the things we see now? I mean, every time we think we've seen the strangest of the strangest, the weirdest of the weird, the universe taps us on the shoulder and whispers "Pssst... look over there..." and we turn around and there's some gorram unbelievably freakish impossible new weirdest of the weird thing staring at us from the Black...
When I was young and saw my first pictures of Olympus Mons and Valles Marineris I thought they were the most amazing things I'd ever seen, or would see. In the years that followed I saw phlegmy volcanoes of bubbling sulphur on Io... the cracked frozen-coffee surface of Europa... Earth as a "pale blue dot" from the edge of the solar system... a "Death Star" orbiting Saturn... the "Pillars of Creation" through Hubble's eyes... the surface of Titan, the crumbling cliffs and steep slopes of a half mile wide crater blasted out of Mars, Earth as a "star" through a gap in Saturn's rings, the sun setting behind mountains on Barsoom, Europa rising up like a phantom from behind the limb of Jupiter, streamers and ribbons of blue flame inside then plume of a volcano vomiting out of Io... ... and now this, this tiny Saturnian moon of crackling ice and accumulated scrunching snow that looks like every UFO I ever drew on the covers of my school exercise books as a kid... Seriously, I mean it, does anyone else ever just sit back from their screens, looking at these images, and think... Unbelievable... just unbelievable... -------------------- |
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Jun 14 2007, 09:08 PM
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#38
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Senior Member Group: Members Posts: 2922 Joined: 14-February 06 From: Very close to the Pyrénées Mountains (France) Member No.: 682 |
Yes Stu, we must admit that Nature has much more immagination than us, poor humans. I've been told of this a long time ago but I'm sure the one that told it too me would be washed away again and again as I am. This is the beauty of unmanned spaceflight : get close to "objects" no reachable in the immediate future directly by humans... this is why I log so often here on UMSF (1001 and counting...)
Thanks again Stu for sharing your feelings so emotionaly -------------------- |
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Jun 14 2007, 10:22 PM
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#39
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Member Group: Members Posts: 813 Joined: 29-December 05 From: NE Oh, USA Member No.: 627 |
Stu...
I have been seeing the marvelous and bizzarre since the 60's.... that first look at Earth from the Lunar Orbiters.... aahhhhhhhhhhhhhhh have to run but... yes, even though I am older than the space age, I am still constantly amazed and grateful for living in this time. And I am constantly blown away by what I see and what is hinted at to come and who knows what wonder tomorrow will bring..... and glad to be an UMSFer. Craig |
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Jun 15 2007, 03:27 AM
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#40
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
Yes, Stu. I do.
Reminds me of a song lyric from the musical "1776": "Is anybody there? Does anybody care? Does anybody see What I see?" -the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Jun 15 2007, 03:57 AM
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#41
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Member Group: Members Posts: 259 Joined: 23-January 05 From: Seattle, WA Member No.: 156 |
... I'm going to show my ignorance here, but presumably Atlas is not tidally-locked to Saturn, leading to roughly equal accretion of ring particles around the equator, rather than them piling-up preferentially on the leading hemisphere. If not tidally locked, then it lends wait to the theory of the rings (and embedded moons) being the result of the disruption of a body that wandered too close to Saturn, and that the rings themselves are a (cosmologically) fleeting phenomenon that we're very privileged to see. Not sure if Atlas is tide-locked or not, but I could see an initially tide-locked Atlas piling so much stuff up on its leading face that it would then have to rotate to maintain equilibrium; and then gradually becoming tide-locked again. Atlas may alternate between tide-locked and asynchronous rotation. The odd cross-section of Atlas's equator may be hinting at this. |
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Jun 15 2007, 04:00 AM
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#42
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Member Group: Members Posts: 259 Joined: 23-January 05 From: Seattle, WA Member No.: 156 |
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Jun 15 2007, 04:00 AM
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#43
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Senior Member Group: Members Posts: 1281 Joined: 18-December 04 From: San Diego, CA Member No.: 124 |
OK... this is getting too weird - Alton Brown, Cohen Bros. films, 1776, Monty Python.... all faves of mine. I hate to say it but there appears to be an elite eclectic cultural demographic shaping up here at UMSF. All I need to find is a Swann and Flanders fan here...
-------------------- Lyford Rome
"Zis is not nuts, zis is super-nuts!" Mathematician Richard Courant on viewing an Orion test |
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Jun 15 2007, 07:26 AM
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#44
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
ON ATLAS’ SHOULDERS…
To their visor-shielded eyes as they approach me - their gaze constantly drawn away by Saturn’s swirled-syrup clouds and icy, jewelled rings – I’ll seem a thing bizarre; a saucer-shaped albino freak drifting meekly through the dark, peeking at the planet’s pastel-painted face from the safety of ring-shadows wide enough to swallow worlds… But when Sol rises from behind - then blazes above – my peaks they will see me as I really am: proud and noble Atlas, a Titan’s tortured son, born of ice and dust, a hoarfrost-crusted starstone left weary beyond words from carrying the sky upon hunched shoulders of ancient rock and boulders, draped by layers of ring-snow folded over and over and over… Finally, after a nervous landing they will stand on me, turn their visors to the sky - but see only black: Saturn’s sulking, bulging bulk an ink stain on the star-sewn cloth of night, an Ultreyan abyss in the sky spotted here and there by flashbulb lightning sparks against the darkness; fluttering auroral flames playing round its poles while his rings, a razor-thin blade of flaming, brittle light, slice him clean in two – - until finally bright Sol appears, spears of light stabbing out from behind Saturn’s great curved limb for a heartbeat before the star itself explodes into view. A nuclear fireball of purest white, God’s floodlight shining on my landscape! No escape now from the Truth: they stand upon a tiny world, an ice grain whirling round a whale, pale and frail against its side… Look, they’ll cry – snow! and staring at the sky will see a billion firefly specks drifting through the high vault of the heavens; playful faeries flitting in the light of Saturn’s sudden dawn, each flickering flake a refugee fleeing from the planet’s rings; too-small-to-fall-in-anything-but-silence things that on their own are nothing, but over aeons have gathered round me like a skirt of dirty lace. And golluming over me, belly-sliding over the crumping snow they'll know, and feel it in their brittle bones that gravity is but a memory here, out where the air is thick with flakes of Saturn's Death Star'd moon... -------------------- |
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Jun 15 2007, 08:58 AM
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#45
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Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
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