Mars Soil Frustrates Phoenix Again

Tablizer writes "The Phoenix Mars lander has been frustrated yet again by Mars's odd soil. The wet nature of the soil they are targeting appears to have made it get stuck in the scoop rather than drop into the oven. Past problems with similarly clumpy soil may have damaged the lander because the vibrator had to be used longer than it was designed for, resulting in a short circuit."

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[Anonymous Coward]

This would make my day. I'm a girl btw :)

Re:One sad conclusion

[typo83]

You ever run a front end loader? In January when the temperature is 9 below zero Fahrenheit? You know the 'scoop' on the front of the loader is called a 'bucket'? What happens when the loader operator digs into a pile of steaming coal, or gravel? The material is 'steaming' because it is warmer and wet than ambient air. The bucket is -9 degrees F, and the material freezes in the bucket. What does come out of the bucket goes into a dump truck (in some cases), where it freezes to the inside walls, corners and bottom of the dump body. At the end of the day, the truck driver, and the loader operator have to dig that material out by hand, with a shovel. Been there, done that. Why would it be any different on mars with colder temperatures, and 38% earth normal gravity?

Not wet

[katakomb]

The word "wet" implies the presence of a meaningful amount of liquid water. In this regard, the soil at the site is very unlikely to be wet (and note that the linked articles don't actually say that it is). The temperature and pressure conditions at the site only allow for solid and gas phases for H2O. Solid ice slowly converts to gas through sublimation when the ice is exposed by the scoop. Materials can clump for a variety of reasons. For example, lunar soil can cling to itself and to things like spacesuits even though absolutely no water is present at all. All sorts of factors can influence the cohesion of planetary soils, including the physical shapes of soil grains, the electrostatic properties of the grains, binding by spatter through micrometeorite bombardment (unlikely on Mars due to atmospheric protection) and, in the case of the Mars soils, even small amounts of ice have the potential to bind grains.