Marsis, at last

Let's none of us expect this to become a place where there's regular posting again just yetawhile (and I certainly won't assume there's much visiting) but it's worth pointing out that the Marsis antenna deployment is finally over. The process has taken a long time; the first antenna deployed crookedly, but then got straightened out; then people got busy analysing why it had not deployed by the book. Clever attitudinal things were done to the spacecraft. And then the second antenna got deployed pretty straightforwardly a few days ago, and the third (much shorter) a few days after that. Three antennae out and an unscathed spacecraft -- that's good news.

According to the BBC the instrument may have started taking data today. It's a pity it's so late in the season; they won't be getting much high latitude northern hemisphere stuff now, which was one of the attractions of a spring deployment. And of course we still don't know what the data will look like, and how robust the interpretations that will be made from them will be. But there is now an operational radar orbiting Mars with the potential for probing the subsurface.

With my head off the Mars game at the moment I was about to end the post "...and so a third dimension is going to be added to our understanding." But then I caught myself. A third dimension is going to be added to our mystification.

Deployment of understanding will take a lot longer.

Comments

[Joe Mansfield]

Nice to see you're not totally offline Oliver. Looking forward to your next project whatever that is.

[Rick Sterling]

Mars Express radar ready to work. http://www.esa.int/SPECIALS/Mars_Express/SEMEV82DU8E_0.html

[BruceMoomaw]

Let's hope it DOES work -- there is a very real chance, given the huge amount of iron in mars' crustal material, that radaar sounding can't penetrte more than a few meters into the surface. (There is also a very good article in the May 19 "Nature" on the extreme difficulty of properly interpreting radar sounding data even under optimal conditions -- the Apollo 17 team almost went nuts trying to do so: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=37206# .)

If this technique turns out to be unusuable, the only possible way to detect deeply buried Martian water or ice will be through using ground-based seismic or electrotelluric techniques, which will be a pain in the neck. Still, even radar sounding that penetrates only a few meetrs would definitely have its uses.

[Dwayne Day]

Glad to see you're back. Other space blogs generally suck. Too much 'tude, not enough information.

Oliver, e-mail me. I cannot find your e-mail on this blog.

[Lance]

Interesting Hypothesis, would love to hear any of your educated comments.

Re: Possible Habitable Ultraviolet Light Protection Zone on Mars for Phtosynthetic life forms

Paper: astro-ph/0507317
Date: Wed, 13 Jul 2005 10:40:53 GMT (888kb)

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 of the H2O ice layers (for
instance snow-like layers). 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)