Space Time Zone

With NASA going back to the moon, Elon Musk going to Mars, and various other countries and corporations planning lunar and planetary trips and new space stations, International scientists and engineers have been debating how they will tell time in space, since there that are no days, months, and years, let alone time zones, and clocks move at slightly different speeds in other inertial reference frames.There is agreement that it is important for communication, cooperation, and safety that there be a single time standard  everyone, a Universal Time for the solar system. 

As recently reported by the Associated Press, the European Space Agency hosted a meeting in the Netherlands last November to discuss the issue. Earth and Mars already have time systems, such as the Mars Sol Date, which counts Martian days, or "sols," and divides them decimally. A Martian sol is 39 minutes and 35.244 seconds longer than an earth day. Today is MJD 60035.7, or April 1, on earth, but on Mars, it is MSD 53055.0. Every other planet has a different rotation period, not to mention years. 

The natural cycles that govern time on earth are earth days, lunar months, and solar years. Julius Caesar got us to stop tracking the moon. There are no yearly seasons in space. The only cycle that we can't ignore is the diurnal one, to which we are naturally synchronized by sleep. Therefore, the new system will only count days. To avoid confusion with earth times, it will also avoid using hours and minutes, and divide the day decimally. The most useful decimal period is one percent of a day, or a centiday, which is close to a quarter hour in earth time. For more precision, there are millidays and microdays. Instead of weeks, months, and years, we have decadays, hectodays, and kilodays. And someday, maybe we'll take our new system of times and dates to the stars, and have star dates.