James M. Graham and Kandis Elliot, University of Wisconsin-Madison, Madison, WI 53706
Science fiction writers have been devising calendars for Mars since the 1950’s. The first working calendar, however, appeared in Mars Scientific Model (Michaux and Newburn 1972). Gangale (1986) described a Mars calendar of 24 months which began with the landing of Viking 1 (July 20, 1976). More recent proposals include those of Zubrin (1993), Becker (1994), and Suraq (1997). Since the number of days or “sols” in a Mars year is fixed at 668.59, calendars differ mainly in the way the year is divided into months.
In our calendar the Martian year is divided into 20 months named for the Greek gods and goddesses of antiquity. Months are arranged in four groups of five months each in which the first three months have 33 sols and the last two 34 sols. The last month of the year (Zeus) has 34 or 35 sols if the Mars year has 668 or 669 sols. The calendar begins on the date of the landing of Viking 1, which is 1 Poseidon, year 0. Days of the week are named for the Sun and first six planets (Solday, Mercuryday, Venusday, etc.). Although the Martian year begins on the first day of northern spring on 1 Eos, this special edition of our calendar, which is called the Millennium Mars Calendar, has been synchronized to the Earth calendar to cover the interval from Dec. 20, 1999 to February 1, 2002, the turn of the millennium.
Each month on the calendar features a full-color illustration, an essay on a selected feature of Mars, a brief discussion about the Greek deity for whom the month is named, and notes about events in the history of space exploration. Separate essays discuss colonization, terraforming and the Martian meteorite ALH84001. The calendar is intended to be both educational and entertaining while stimulating interest in the exploration of Mars. The Millennium Mars calendar is one of many possible forms for a Mars calendar. Future colonists of Mars will no doubt adopt a calendar which serves their needs best in their new environment.