Where the Minutes Are Longer: The Weird Science of Telling Time on Mars

Time ticks by a bit more slowly on the Red Planet.

Mars24 via Smithsonianmag.com

Part of the joy of following NASA's Curiosity mission thus far hasn't been the science(!!!) or, the discoveries (!!!), but the way in which NASA has entertained us, streamed us into mission control the night of the landing, tweeted at us in the voice of the rover, and even egged the Internet on as it enthusiastically memed a cute scientist.

Now, for the truly nerdy among us, NASA is also providing us with an app, Mars24, that provides the time of day on Mars for the locations of the different rovers and other Martian landmarks, according to Joseph Stromberg at Surprising Science. A map of where it is currently day and night on Mars is also included (shown above).

Mars24 via Smithsonianmag.com

Time on Mars isn't just a conversion the way that we add or subtract hours to change time zones here on Earth. Mars actually spins a bit slower than our own planet, and as a result, its whole day is a bit longer -- 24 Earth hours and 39 Earth minutes. (This means that the 3037 Sols -- Martian days -- that Opportunity has been on the planet is something close to 3119 Earth days.) But the convention is to still use a 24-hour day with a 60-minute hour, meaning that each minute on Mars last longer than each minute on Earth.

For scientists who work on the Mars missions, this can mean that the schedule of their work shifts by 39 minutes every day. A wonderful little story about this came out of the 2004 Opportunity landing. As Julie Townsend, a Mars rover team member explained at the time, "Everything on this mission is based on local solar time on Mars. From home, during the mission practice tests, it was very difficult to constantly translate Earth time to Mars time." So the team turned to master watchmaker Garo Anserlian to craft special Martian-time watches.


The face of Anserlian's Mars watch.

"Since I was a young child I've put my heart into making very precise time pieces, now I was being asked to create a watch that was slow on purpose," Anserlian mused. He spent two months designing and building his Martian clock, attaching tiny lead weights to slow the wheels and hands. His first effort was only off by 10 seconds, and from there, he fine-tuned it to get it exactly right. Once he had his working model, he could replicate it pretty easily for anyone on the rover team who wanted one. Anserlian told NASA that when he watched Opportunity land, "I felt proud; I got goosebumps. I saw that some of them had two watches on and I thought, one of them was mine! I was proud as an American that it landed and secondly that my watches will be used."