Martian Cartography Options

[karolp]

I have recently freaked out a little bit about Martian maps of all sorts. And finally I was astonished with those highly detailed beauties that I list below. Nonetheless. some of them have huge inconsistencies (crater names) easily noticed when we compare the surroundings of Gusev crater. Enjoy:

http://www.ralphaeschliman.com/
http://planetologia.elte.hu/1cikkeke.phtml...arsmapinte.html
http://pubs.usgs.gov/imap/i2782/

[machi]

Nice map! One comment - the position for Mars 2 should be 10 degrees further east. The position you show is the one reported as "where Mars 2 entered the atmosphere", but it was not travelling vertically to impact at that point, it was travelling to the east at a very low angle. The published locations of atmospheric entry and impact for Mars 6 make it very clear how this worked.

Phil

Thanks and thanks as well for info about Mars 2 (this will be repaired in pdf).

I especially love the color scale used - very nice - it retains that blue 'Oh..was this an ocean??' of the low altitude, but is clearly martian above it. LOVELY work.

D

Thanks! I used altimetry scale similar to that from maps in my old school atlas. I always liked these maps, so I think that's good idea.
And false color images from HRSC (with infrared as red) have similar colors in dependence on elevation. Deeper -> more atmosphere -> bluer, heigher -> less atmosphere -> redder.

CONGRATULATIONS Machi : how beautiful (and useful with all those elevations) !
(PS : I thought that the minimum depth in Hellas was -8,200 m, the USGS figure. Please, how did you get -8,530 m ?)

Thanks!

USGS figure is somewhat weird. Lowest point in Hellas Planitia was measured as -8197.51 meters below areoid. This is information from PEDR MOLA altimetry profiles. But in MEGDR maps, they have lowest point as -8208 meters. And MEGDR maps are constructed from PEDR profiles! I suppose, that this is some minor flaw in interpolation algorithm, which can did some errors (+/- 10 meters in some points). Or this algorithm works with slopes and can extrapolate possible peaks and depressions. I don't know.
Hellas' depth (-8530 meters) in the map is based on HRSC DTMRDR dataset. All data from this dataset are depicted as blue triangles (it is depicted in small legend down in the map). It's not so good visible in jpeg, it's better in pdf.
This dataset has digital terrain models with better local coverage and because of that often with better data for some regions. Authors of this dataset used data from MOLA altimeter as source of true elevations (they mapped elevations in DTM with help of MEGDR maps). Because they used not only same dataset, but also same areoid model, informations about elevation are (in theory) compatible between MOLA PEDR and HRSC DTMRDR.
This (-8530m) information looks weird, but I look at these DTM and MOLA detected lowest point as deep crater and in DTM data, smaller crater (undetected by MOLA) is in the middle of this crater, so this small crater in larger crater (which is in another crater - Hellas Planitia ) is actual deepest point on Mars.

[vikingmars]

This (-8530m) information looks weird, but I look at these DTM and MOLA detected lowest point as deep crater and in DTM data, smaller crater (undetected by MOLA) is in the middle of this crater, so this small crater in larger crater (which is in another crater - Hellas Planitia ) is actual deepest point on Mars.

Thanks a lot Machi for all your good explanations.
Did you make a more detailed hi-res elevation map of the inside of the crater with its small crater in its middle ? (please, see CTX image herewith, with the small crater marked with a yellow "+")