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Name: Taleana
Status: student
Grade: 9-12
Location: ND
Country: N/A
Date: 1/20/2005


Question:
Scientists have recently claimed that the Huygen's probe likely hit and settled into Titan's 'mud' surface. I realize methane, ethane and nitrogen have some rather unique properties but couldsomeone enlighten me as to how any environment with a -180 Celsius surface temperature could produce 'mud'? Has this or could this be duplicated on earth or is this simply speculation?


Replies:
Hi Taleana,

I am going to make a guess at this. "Mud" is formed when soils mix with a liquid. On Earth, we typically associate mud with soil mixed with water. It would seem to me however, that with the temperature on Titan, compounds which we normally associate as a gas, exist in a liquid form. This liquid would then make "mud" with the soils of Titan.

Bob Hartwell


Here the term "mud" does not mean a suspension of sand in water -- the way we commonly use the term. Maybe an alternative would be "slush" which means the suspension of some solid particles in a liquid in such a way to form a deformable aggregate, without specifying what the solid particles and the liquid may be chemically. It is a term describing consistency not composition. The Huygen's probe measures this experimentally by "poking" the surface with a mechanical probe and measuring how the surface responds to the "poke". In principle it could vary from "rock hard", to "rubbery", to "sludge", to "mud", to "high viscosity liquid", to "watery (i.e. low viscosity liquid). This is not speculation. It is a fairly easy determination of the physical properties of the surface of Titan at least in the area where the probe landed.

Vince Calder


Hi Taleana!

we are all very interested and excited about the scientists findings in Titan. The conditions there are completely different from Earths . At Earth Methane and Nitrogen are both gases at normal temperatures occurring here. Methane melting point is -182.48 degree C and Nitrogen is -195.8 degree C at Earth at normal temperature and pressure.

There the conditions are completely different. The fact is that in Titan Methane is liquid. Also there are solids at the surface, hydrocarbons and organic compounds and water, and others that are been studied right now.

In Earth "mud" is soil mixed with water, kind of suspension. In Titan what was called "mud" probably is these solid particles at the surface mixed with methane.

Right? But prepare yourself for a lot of surprises, coming from Titan. Quite a long time ago, around the beginning of eighties some scientists knew already many facts about Titan "atmosphere" and surface. But now the data are coming from there, it is great isn't? We can "see" things actually.

Thanks for asking NEWTON.

Mabel
(Dr. Mabel Rodrigues)


I believe I saw an interview of the scientist who made that statement. The statement was based on the preliminary data obtained from an instrument that was attached to the bottom of the probe. This instrument was essentially a force-measuring device that would give data on the kind of surface the probe landed on based on the kind of forces that were imparted to the instrument on landing. As it turned out the force-profile detected by the instrument was similar to the force-profile that scientists here on Earth have detected when they drop the instrument onto mud or heavy sand.

On a first-principles basis, the freezing point of nitrogen is -210 deg-C, that of methane is -182 deg-C, and that of ethane is -182 deg-C, so you can imagine how this combination could give the consistency of mud.

Greg (Roberto Gregorius)



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