THE DARIAN SYSTEM

Abstract

Figures and Tables

1.0 The Darian Calendar for Mars

1.1 Introduction

1.2 Years

1.2.1 An Extended Intercalation Scheme

1.3 Months and Seasons

1.4 Weeks

1.4.1 The Martiana Calendar

1.5 The Telescopic Epoch

1.6 Darian-Gregorian Calendar Displays

1.7 Children and Collateral Relatives

2.0 The Calendars of Jupiter

2.1 Introduction

2.2 Circads

2.3 Years

2.4 Weeks

2.5 Months

2.6 Intercalation

2.7 Calibration

2.8 Variations on a Martian Theme

3.0 The Darian Calendar for Titan

3.1 Overview of the Darian Calendar System

3.2 Astronomical Cycles on Titan

3.3 Circads and Weeks

3.4 Months and Years

3.5 Intercalation

3.6 Calibration

4.0 Conclusion

5.0 References

Appendix 1: Intercalation Precision on Mars

Appendix 2: Perturbations of Mars

Appendix 3: Martian Daylight Time

THE DARIAN SYSTEM

Copyright 1986-2005 by Thomas Gangale

APPENDIX 2: PERTURBATIONS OF MARS

Gravitational perturbations by the other planets result in year-to-year variations in the length of the several types of Martian astronomical years. During the Martian years 141-275, the vernal equinox year (Figure 14) varies by 0.065 sols. The variation in the length of the summer solstice year (Figure 15) during this period is of the same order, 0.051 sols. The autumnal equinox year (Figure 16) and winter solstice year (Figure 17) vary by about twice as much during this period, 0.099 and 0.103 sols, respectively. The variation in the anomalistic year (Figure 18) is an order of magnitude greater than that of the vernal equinox year, 0.496 sols. This data was calculated from "A post-Pathfinder evaluation of aerocentric solar coordinates with improved timing recipes for Mars seasonal/diurnal climate studies" by Michael Allison and Megan McEwan.

Figure A2-1
Variation in the Vernal Equinox Year, Years 141 to 275

Figure A2-2
Variation in the Summer Solstice Year, Years 141 to 275

Figure A2-3
Variation in the Autumnal Equinox Year, Years 141 to 275

Figure A2-4
Variation in the Winter Solstice Year, Years 141 to 275

Figure A2-5
Variation in the Anomalistic Year vs. Vernal Equinox Year, Years 141 to 275