| Risultati della ricerca nelle immagini - "Models" |
032-Mars_Interior.jpgWhat's inside Mars?175 visiteMars interior is simply modeled as a core and mantle with a thin crust, similar to Earth. Mars' size and total mass are known. Given four parameters, the core size and mass and mantle size and mass can be determined.
The combination of Pathfinder Doppler data with earlier data from the Viking Landers has determined a very important parameter, the "Moment of Inertia", through measurement of Mars' precession rate. A fourth measurement is needed to complete the interior model. This may be achieved through future Doppler tracking of Pathfinder, since the presence of a fluid core may be detectable through its effect on Mars' nutation. The determination of the moment of inertia is a significant constraint on possible models for Mars' interior. If the core is as dense as possible (i.e. completely iron) and the mantle is similar to Earth's (or similar to the SNC meteorites thought to originate on Mars) then the minimum core radius is about 1300 Km. If the core is made of less-dense material (i.e. a mixture of iron and sulfur) than the core radius is probably no more than 2000 Km.
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033-Mars_Rotation.jpgMars' Rotation and Orbit Dynamics131 visiteMars rotation around its pole causes a signature in the data with a daily minimum, when the Lander is closest to the Earth. Changes in such a daily signature may reveal information about the interior of Mars, through its effect on Mars' precession and nutation.
The signature is also sensitive to variations in Mars' Rotation Rate, as the mass of the atmosphere increases and decreases along with the Polar Caps increase and decrease (obviously the Polar Caps increase during the Martian Fall and Winter and then, due to the higher heating of the Planet - and subsequent evaporation phoenomena - they decrease in Spring and Summer).
Long term signatures in the range to the Lander are caused by asteroids perturbing Mars' orbit; an analysis of these perturbations may allow us to also determinate the masses of these asteroids.
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Controversial_Features-The_Villa-AB108405-SF-03.JPGUnusual Squared Structure on Mars (4)70 visiteMa lasciamo ora che sia il Dr Mc Cann a dirci la sua:"...This image (si riferisce al frame precedente) shows a sheer cliff with a very large ledge in its midst. On that ledge is a large two story structure, the first floor walls of which are facing camera and in shadow. The second floor is a well defined SQUARE and is turned at a precise 45° angle to the first floor. CENTERED in the midst of the roof of that squared second floor is an abrupt, sharp circle..a "landing pad" as for helicopters atop tall buildings and on decks of ships. UP and to the RIGHT of the building structure there is a culvert/conduit or PIPE with an open top which comes forth out of the upper cliff face. There is a fluid streaming from the end of the "U" shaped pipe and is blurred as it falls down to the ledge. The fluid hits the ledge and erodes a wavy channel to the edge of that ledge and then cascades down the lower cliff face to disperse in a deltaic pattern on a talus cone..." (continua)
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