Mars Clock

  Keeps 24 hour mean solar time on the planet Mars

Now you can keep track of what time of day it is at the Mars Rover landing sites. A Martian day is very close to an Earth day --- about 24 Earth hours plus 39-1/2 minutes. This means a normal quartz clock can't keep Martian time. We have created a quartz clock with a timebase adjusted to conform to mean Mars time. The clock divides the Martian day into 24 hours. Once you have set the clock to the local Mars time at one of the Mars Rover locations, you can tell at a glance what time of Martian day it is for the rovers.

The clock has a 24 hour dial with a seconds hand and runs on four "AA" batteries. A wheel on the back of the movement allows you to make coarse adjustments to the time displayed. A small circuit board with two push buttons allows precise synchronization of the second hand. One button causes the second hand to advance at twice normal speed. This makes it possible to advance the time if the clock is slow. The other button stops the clock until the first button is pressed. This allows you to stop the clock for a while if it's fast.

The clock is hand-tuned to run within one or two parts per million of the mean Martian rate. The clock should be accurate to one or two seconds per week.

The current Martian time at the Rover landing sites can be found at the Nasa web site: http://marsrovers.jpl.nasa.gov/home