I was really hoping you and Alex would add your input!

If you look at the landing site photos and compare to the pre-landing VR relisations and CGI movies, you will see that Gusev (note spelling, all of you, no "t") is exactly as advertised.

It is a flat smooth rolling plain with low rock abundance. In short it is boringly safe. The MER site selection process worked on safety first, safety second, safety third, and science last. We were not allowed to land in the places that would be really interesting, because the overwhelming drive after MPL was to land safely.

Given that, the least bad sites were chosen from a rather unexciting list EXCEPT that the occurrence of haematite (english spelling optional) fits one of the central planks of the "water on Mars" story. Therefore it is inevitable that it was selected, once it passed site safety analysis.

So, Nick- if safety was ignored as a factor, what site would YOU choose and what site would you think the entire Mars reasearch community would settle on?

I make the distinction between you individually, and the community because each individual researcher has their own area of interest, and the community would have to choose a site that offered to make as many happy as possible...

Effectively, everyone (me included) "voted" for the Hematite Site (American spelling likely to become official planetary nomenclature). After that, it was a question of which site came second (or in my cynical view, least last).

Gusev would be a great place to land if we had a tracked or well-wheeled rover with autonomic driving capability that could clock up 20-50 km of travel and reach some useful outcrops, like those tantalising hills in the middle distance, or the fascinating knobby/etched terrain further to the east. We don't have that rover and will get a maximum of 1 km from the landing spot, stopping on the way to look at a whole bunch of small scattered rocks that appear interesting in various different ways.

given the terrain, my prime target for study would be the shallow crater visible nearby the lander... looking at rocks along the way. Given the _apparent_ size of the rocks I think evidence of sedimentary layering will not be found. If some of the rocks are sedimentary, evidence of evaporates would nail down aquatic vs wind borne deposition... either way the microscope should be used a lot- (anyone know how small a feature the scope can see?

The real "evidence" of water in Gusev (at least 3 billion years in the past, btw) is only likely to be found where earth movements have thrust up buried layers or where impacts have excavated deep into the old dusty surface. We might get lucky and find that some of the rocks scattered sparsely aout are really interesting, or we might not. The best places in Gusev crater for signs of water (or whatever the fluids were that carved the channels) are further to the south, where the feeder channel actually enters the crater and a delta-like lobe is "built" on the surface (or differentially eroded out of it). Unfortunately, we couldn't fit a safe landing ellipse there, so we chose to land far to the north and hope to pick up chemical signs of ancient water.

That 3 Gyr number is depressing... in that time so much detrius would have filled the crater that the lakebed would be deeply buried... however the position of the landing site and the nearby presence of craters in the lakebed give me hope that the larger rocks likely came from lakebed impacts and thus may be from the original lakebed (Is that a reasonable hope, Nick?).

(When I say "we", I mean the Mars community. I had my share of input too, and therefore I share in the concensus decision. Given the constraints on landing, I think we have selected one good site and one other as a backup. And, to be fair, since we understand Mars so poorly, ANY landing site is a new test of the planet's geology and will turn up some new, unsuspected, odd, and perhaps insightful data.)

Of course you dont have to answer this, but just out of curiosity- Did these meetings to choose a site get heated, or given the list of sites, were the sites easy to choose?

Now let's look forward to panoramas and photos in unprecedented detail, to microscopic pictures for the first time, and for some new insights into mineralogy and composition from the range of new and improved instruments.

And please, let Opportunity get down safe because I'm dying to know more about the haematite!

AMEN!