![]() |
|
|
Thread Tools | Display Modes |
|
#1
|
|||
|
|||
![]()
In this morning's astro-ph:
Paper: astro-ph/0507317 Title: Radiative Habitable Zones in Martian Polar Environments Authors: C. Cordoba-Jabonero, M.-P. Zorzano, F. Selsis, M. R. Patel and C. S. Cockell Comments: 44 pages, 8 figures Report-no: CAB-lcasat/04057 Journal-ref: Icarus 175 (2005) 360-371 DOI: 10.1016/j.icarus.2004.12.009 The biologically damaging solar ultraviolet (UV) radiation (quantified by the DNA-weighted dose) reaches the Martian surface in extremely high levels. Searching for potentially habitable UV-protected environments on Mars, we considered the polar ice caps that consist of a seasonally varying CO2 ice cover and a permanent H2O ice layer. It was found that, though the CO2 ice is insufficient by itself to screen the UV radiation, at 1 m depth within the perennial H2O ice the DNA-weighted dose is reduced to terrestrial levels. This depth depends strongly on the optical properties ofthe H2O ice layers (for instance snow-lile layes). The Earth-like DNA-weighted dose and Photosynthetically Active Radiation (PAR) requirements were used to define the upper and lower limits of the nortern and southern polar radiative habitable zone (RHZ) for which a temporal and spatial mapping was performed. Based on these studies we conclude that phtosynthetic life might be possible within the ice layers of the polar regions. The thickness varies along each Martian polar spring and summer between 1.5 m and 2.4 m for H2= ice-like layers, and a few centimeters for snow-like covers. These Martian Earth-like radiative habitable environments may be primary targets for future Martian astrobiological missions. Special attention should be paid to planetary protection, since the polar RHZ may also be subject to terrestrial contamination by probes. ( http://arXiv.org/abs/astro-ph/0507317 , 888kb) -- Lt. Lazio, HTML police | e-mail: No means no, stop rape. | http://patriot.net/%7Ejlazio/ sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html |
#2
|
|||
|
|||
![]() At 30 mw/m2 worth of a near surface geothermal radiative heat flux and, at times not actually all that much better contributed from the sun, a Mars polar habitat zone that's covered by such a thick crystal composite of mosly CO2/dry-ice had best plan upon forgetting about utilizing whatever safe levels of UV by going deep, at least a km if not deeper and, taking along a good cash of plutonium for energy and auxiliary radiative heat to boot. This fresh SETI topic (as generated by Alfred A. Aburto Jr.) "Life in solid ice" as having provided us with this following research link that's sharing absolutely terrific information about the potentials of their being other such life within ice; http://xxx.lanl.gov/ftp/q-bio/papers/0507/0507004.pdf With a little spare (imported) energy one can easily generate artificial amounts of UV-b and UV-a (perhaps affordably as great as 1 w/m2 per scientific working habitat), not to mention the secondary/recoil worth of visible plus whatever waste thermopile IR heat spectrums as well. Suggesting that Martian life somehow became naturally evolved as becoming sub-frozen sequestered DNA/RNA, as for their relatively abrupt environment shift upon Mars getting summarily pulverised, as for their having to survive by going deep into a sub-layer of H2O/ice isn't exactly all that doable unless some form(s) of applied (ETI to us) technology are responsible. Dormant if not dead forms of sequestered Martian life, little more than microbes and/or spores trapped deep into the likes of H2O/ice or even salty/comet deposited ice is doable, although especially doable under that ice if there's any remains of an ocean or even slight pools of geothermally sustained environments which you'd think should be chuck full of such Martian life. Although, I'm thinking mostly of that form of sequestered life as having become non-photon and thus mostly chemically reactive, which we haven't much of anything similar upon Earth until going extremely deep into our oceans, though even that form of life has formed viable ways of generating their own photons, and/or of having shifted their biological and visual evolution toward the geothermal IR spectrum. Robotically going for such deep Martian life as a continuing level of our nearly mad science research is going to remain as horrifically spendy, as well as each mission and for all those nice folks employed will be continually consuming talents, resources and thereby polluting for mother Earth in far more ways than the mere fire and brimstone launch phase, not to mention potentially lethal aspects if our pro-Mars or bust wizards actually manage to retrieve such items from Mars. Humanly going for the likes of Mars is absolutely insane beyond the "high standards and accountability" standards of even our "so what's the difference" LLPOF level of incompetence and arrogance represented our resident warlord(GW Bush), that is unless we've established such a technological and scientific quest as being a one-way ticket to ride, or by way of having established their lifetime safe-house as situated upon our moon. Of course, going for Venus is almost too easy, especially when at times it's merely a little better than 100 fold as far off as our moon, as well as there's no apparent need for a given mission (robotic or otherwise) having to bring along spare energy. Obviously there's not much chance in hell of there being any ice upon Venus. However, with such easily available green/renewable and thus squeaky clean resource of energy there's no apparent nor insurmountable limits as to what can be artificially sub-frozen, or otherwise easily processed into just about anything you can imagine. Thus robotically and even humanly accessible is where the relatively hot but not actually all that nasty environment of Venus has been doable, especially if you're situated as somewhat elevated and migrating yourself from time to time as for residing within the extensive season of nighttime, within an environment that's corrosion free, essentially fire-proof and absolutely crystal clear (other than for geothermal S8 venting) for a good 25+km in all directions and, actually only a wee bit dark to human vision but nocturnally and/or applied technology making the nighttime season just fine and dandy. Since terrestrial ice doesn't so easily just happen for the inner most creation of planets. Unlike a mostly sub-frozen, easily pulverised and TBI to death Mars, a sufficient volume of raw ice is exactly what a geothermally hot Venus needs if to accommodate the wet forms of life as we've known about, just as it was the necessary influx of such massive snowballs and/or horrific shards of icebergs as pulverised away from an icy proto-moon upon initial and subsequent secondary impacts generating such nasty icy spacebergs that eventually gave mother Earth a badly needed cooling-off shot in the dark at creating and sustaining life as we know it, that is unless our sun started itself up gradually instead of any result of a big or little bang, or having arrived somewhat after the fact seems almost impossible. A couple of related although officially banished/taboo topics: Getting Sedna into orbiting Venus http://groups-beta.google.com/group/...74d 05e31f6ee MOON Physics at 1% the cost of doing Tempel-1 http://groups-beta.google.com/group/...75214f0e833df4 ~ Venus Life, a Township, Bridge and ET/UFO Park-n-Ride Tarmac: http://guthvenus.tripod.com/gv-town.htm Russian/China LSE-CM/ISS (Lunar Space Elevator) http://guthvenus.tripod.com/lunar-space-elevator.htm Other Life on Venus, plus sub-topics; Brad Guth / GASA-IEIS http://guthvenus.tripod.com/gv-topics.htm |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
New Martian Meteorite Found in Algeria: NWA 3171 | Ron | Astronomy Misc | 0 | August 20th 04 10:07 PM |
Planetary Systems With Habitable Earths? | Rodney Kelp | Policy | 6 | April 2nd 04 02:32 PM |
ESA's Martian weather report (Forwarded) | Andrew Yee | Astronomy Misc | 0 | January 15th 04 05:10 PM |
Mars Is Melting | Ron Baalke | Science | 0 | August 7th 03 09:19 PM |