New Mars Express And Huygens Results, ESA conference - November 30, 2005 Options

[Guest_paulanderson_*]

http://www.esa.int/esaCP/SEMA96ULWFE_index_0.html

Relating to Mars Express:

"At the same time, ESA’s Mars Express mission is continuing its investigations of Mars, painting a new picture of the 'red planet'. This includes the first ever probing below the surface of Mars, new geological clues with implications for the climate, newly-discovered surface and atmospheric features and, above all, traces of the presence of water on this world."

[RNeuhaus]

About the title Radar reveals ice deep below Martian surface

They believe a 250-kilometre-wide circular structure that lies between 1.5 and 2.5 kilometres below the surface of Chryse Planitia is an impact crater that was buried with volcanic ash or soil several billion years ago. The team sees no radar boundaries in material that fills the bowl of the crater and the radar signals lose little strength when passing through it. That suggests the infill must contain a large proportion of ice, which is nearly transparent to radar.

I think it would be probable that there is water at the bottom of impacted crater. Since the crater is 250 km (rather bigger than Gusev's ones with 160 km diameter).

It is located so deep at 1.5-2.5 kilometers under the surface. Then I deducted that the area: Amazonis, in the north plantias has no craters on it must have be resurfaced after the Hesperian ended, since otherwise many craters would have been formed on it.
See the following picture:
The impactors that formed the large basins Isidis, Hellas, and Argyre were so large that there were *never* enough of them to uniformly cover the planet, even in the Noachian. Examine this detailed map of Isidis.

The Isidis crater has 1,125 km diameter
Note that it is very smooth, and is about half surrounded by cratered terrain, and half surrounded by a smooth plain. This suggests that whatever filled in the Amazonian surface flowed into Isidis, but could not cover the southern walls of the basin. Remember from the discussion of the crustal dichotomy that the northern lowlands are lower, and hence easier to cover.

Of course, this discussion is very simplified. There are stratigraphic relationships (like the boundary of Isidis) that are used to determine relative ages, in addition to crater counts. The maps shown here display craters larger than about 100 km, and this can be done more accurately using many thousands of smaller craters (recall from our discussion of crater forms that a 100 km crater is a large crater on Mars.) Also, there are complex curves for the number of impacts of a particular size: the division into three periods is fairly arbitrary.


The major volcanoes can be found on the youngest, Amazonian surfaces. This is to be expected, since the Amazonian surfaces were recently covered by lava and are thus volcanically active. However, it is a misconception to believe that the lava that covered these surfaces came from the visible volcanoes. Instead, these areas are volcanic plains, usually formed from fissures which are then subsequently covered by the same lava that flooded the surrounding areas.

Finally, the found hidden craters in Amazonis Plantias might be true but according to the radar reflection and the shape of the bottom surface (smooth curvature), might lead as an old water deposit.

Rodolfo