Mars skepticism

While most things space related interest me, I don't often blog about Mars missions. I don't begrudge planetary scientists their fun, and good science may still come out of these missions; but really, I am skeptical of any optimistic talk of finding life on Mars, or indeed of manned missions.

For humans to travel to Mars, there is a major issue with space radiation. Even on the surface, it's not shielded by a decent atmosphere (or magnetosphere?) and the radiation environment is not so good for permanent living. (Unless you have shielding, the easiest of which is to live under dirt.)

As for bacteria, this summary of a recent paper indicates that any bugs would have to be far underground:

The damaging effect of ionising radiation on cellular structure is one of the prime limiting factors on the survival of life in potential astrobiological habitats. Here we model the propagation of solar energetic protons and galactic cosmic ray particles through the Martian atmosphere and three different surface scenarios: dry regolith, water ice, and regolith with layered permafrost. Particle energy spectra and absorbed radiation dose are determined for the surface and at regular depths underground, allowing the calculation of microbial survival times. Bacteria or spores held dormant by freezing conditions cannot metabolise and become inactivated by accumulating radiation damage. We find that at 2 m depth, the reach of the ExoMars drill, a population of radioresistant cells would need to have reanimated within the last 450,000 years to still be viable. Recovery of viable cells cryopreserved within the putative Cerberus pack-ice requires a drill depth of at least 7.5 m.

Here's another article (based on the same paper, I think) explaining that that scrapping just below the surface is not likely to find anything living.

Really, until they come up with a good answer as to how to ensure astronauts won't be killed during a lengthy voyage to Mars, I just don't know that it is worth the effort to plan for manned missions.

I would much rather intensive investigation of the Moon, with a view to permanent, sheltered bases, to act as lifeboats for humanity.