Mars calendar, mission sols in a standard calendar Options

[Phil Stooke]

This file is something I put together to relate sols for all Mars lander missions to the standard Mars calendar devised by Clancy et al. and now widely used with orbital data. I'm posting it in case it might be useful to others.

It's an Excel file, so it can easily be extended if necessary. Each mission is given three columns, one for mission sols on the surface (some start with sol 0, some with sol 1, according to mission usage), one for the Mars year and one for the sol of that year.

Please note that there may be discrepancies of one sol here and there because I am simplifying things quite a lot here. For instance, MER-A and MER-B are half a planet apart, so their sols are half a sol out of phase, but I'm ignoring that in relating them to the planet-wide sol of the Clancy system. Details of the Mars calendar can be found on Emily's website at:

http://www.planetary.org/explore/space-top...s-calendar.html

(I have made independent lists of Mars historical dates in my forthcoming Mars atlas). And conversions to Earth dates can be made via this VERY useful website:

http://www-mars.lmd.jussieu.fr/mars/time/martian_time.html

Phil

 mars_calendars.xls ( 323.5K ) Number of downloads: 144

[Phil Stooke]

The 1955 start date is designed to be just before the global dust storm of 1956, the first one to be investigated in detail. This calendar system was originally set up for atmospheric studies.

Phil

[mwolff]

The 1955 start date is designed to be just before the global dust storm of 1956, the first one to be investigated in detail. This calendar system was originally set up for atmospheric studies.

Phil

As the citations indicates, it was an essentially arbitrary choice. However, the fact that 1956 was an International Geophysics Year and that it had the best Mars "opposition" for the previous 15 years led to a lot of attention for Mars (including the beautiful imagery in Slipher's book of 1962). So, it was a confluence of things including the dust storm...including the wish to avoid the need to large numbers at present. It was not Clancy's birthday (and he has expressed happiness of not having chosen that year...since he wasn't really thinking about how that would look).

There has been some debate (among a very small number of people) about what would have been a better choice. However, it boils down to the fact that this system is in use and it seems that many of the people who propose different zero-points don't actually use the system.