Mud on face - all round...

A correction to my last blog...

The Oven "Tega" is in fact a house like structure on the flat top of the Phoenix (circled in the picture below).

The schematic diagram which forms the intro picture, copied from the NASA webs shows the position of Oven 4 (the first oven used) so the picture below

is taken from above the oven looking down over the oven doors to the top of the Phoenix. To quote NASA

"The TEGA oven doors are on a surface sloping at about 45 degrees, with the top of the doors near the lower edge of these images. The downhill direction on this part of the instrument appears upwards in the image. The screen-covered opening for the oven intended to analyze this soil sample is between the vertically positioned door at the right end of the series of doors and the partially opened door to the left of that one."

So I retract my comments about the design of the TEGA.

But that soil was incredibly sticky!!!

Referring back to the picture with the soil on the oven doors, it should have fallen away from the viewer into the picture and towards the lens in the middle of the picture - not to the left as I had originally interpreted.

This picture may help to understand what was going on. It shows the digger poised over the oven before "dumping its load".

The TEGA is the dark triangle on the bottom right of the picture and open oven doors are visible and the lens in the centre of the other picture is just visible in the bottom centre of this picture.

As you may know the oven has now received some soil and analysis is now underway as described on Yahoo News

To quote that article "Scientists have been surprised by the clumpiness of the soil at the landing site, which they described as crusty on the surface and looser below." - you mean like it had been baked? I wonder how that happened?

The Nasa site itself says "that the oven might have filled because of the cumulative effects of all the vibrating, or because of changes in the soil's cohesiveness as it sat for days on the top of the screen".

The Daily Telegraph says "The sample, a tiny fraction of a teaspoon, will now undergo its first test, known as a "low temperature bake", in which it will be heated to determine it if contains any ice. Scientists think this is unlikely given that it has been exposed to the Martian sunshine so long."

So one explanation is that the sample was wet and muddy when dropped... and then it dried out.

An alternative explanation which could explain why the sample didn't look like mud would be that the lander is slightly warmer than the surrounding environment. If that is the case then it might explain why the soil is so sticky. The very cold icy mud could melt for a moment on contact with the oven doors and protective mesh and then immediately freeze again as all the available heat was sucked out of the metal just in the same way as ice cream straight from the freezer sticks to a dry ice cream scoop.

After a few days in the dry low pressure Martian atmosphere the ice in the soil sublimated (going straight from solid to vapour like dry ice does on Earth) and having dried out the soil loosens its grip on the mesh and oven doors and falls into the oven. If this is the case, then again this is a bit of a design flaw.

This theory could also explain why the digger arm is now able to sprinkle samples of soil.

If, as I suspect, the whole area was blasted by steam and water as Phoenix landed, the water would freeze on contact with the surface of the surrounding soil but then would slowly sublimate away leaving the dried mud effect of a hard crust with "clumpy bits" underneath.

The stuff the digger scrapes up now is a lot 'drier' (contains less ice) than the stuff it dug up a few days after landing.

This theory will be proved (or otherwise) if the soil scooped from deeper under the surface contains water ice while the surface stuff (and the soil in the oven at the moment) doesn't...

By the way all pictures NASA's not mine (I haven't been to Mars to take them ).