Living on Mars Time: Scientists Suffer Perpetual Jet Lag

Living on Mars Time: Scientists Suffer Perpetual Jet Lag
Morten Bo Madsen sits next to his blue LED light box as he works. The light box is supposed to help extend Madsen's day by regulating his circadian cycle. Madsen, of the University of Copenghagen, works on the robotic arm camera for the Phoenix Mars Lander mission. (Image credit: University of Arizona)

Morten BoMadsen spends his work day crunching data on a laptop seated in front of a clearplastic-covered box about the size of a widescreen computer monitor that emitsa startlingly bright blue light.

No, thisisn't a scene from a sci-fi movie. Madsen is one of the 150 scientists andengineers working on NASA's PhoenixMars Lander mission. The bright light keeps Madsen's internal clock incheck, because Madsen, you see, is living on Mars time.

Phoenix is a $420 million mission with theaim of sampling and analyzing the dirt and subsurface ice layer in the northpolar regions of Mars as it looks for signs that the red planet may have beenhabitable at some point in the past.

Since thespacecraft landed on Mars on May 25, mission controllers have been living onits schedule, or rather the exact opposite of it. When the spacecraft issleeping during the Martian night, the scientists are up analyzing data; whenthe spacecraft rises at the beginning of the day on Mars, they retire and let Phoenix do its work.

This maynot sound like too taxing a schedule, but there are a couple of catches: Mars'day is 40 minutes longer than Earth's, and the start of the Martian day isalways changing with respect to Earth time, as a result of their respectiveorbital motions.

Living on aschedule that shifts forward by 40 minutes everyday can wreak havoc on thehuman body, creating an effect that is essentially like perpetual jetlag.

"Itwould be like traveling two time zones every three days," saidphysiologist Laura Barger of Harvard Medical School and Brigham and Women'sHospital in Boston.

Barger andher colleagues are studying Madsen and 18 other Phoenix team members as theytry to adapt to their Martian schedule, monitoring them for signs of fatigue aswell as providing tips for how to live out-of-sync with the rest of the world.The results could help guide future space travelers and Mars missions.

StudyingMars time

All humanspossess an internal"circadian" clock that runs on a roughly 24-hour cycle, modulatedby the daily shifts between light and dark as the Earth rotates.

"Weknow that light is the most important time cue to the circadian clock,"because it tells the brain what time of day it is and what the body should bedoing, Barger said.

Anyone whohas flown between time zones knows that the abrupt shift in the time of day canthrow sleeping and eating schedules out of whack. The same came happen to swingand night shift workers.

Living onMars time can create the same issues, because "you have sort of a rotatingshift with the Martian day put on top of it," as Barger describes it.

"Weknew from our laboratory work when we simulate people living on a Martian daythat they have misaligned circadian rhythms," she said. "They're notable to adjust. They have problems sleeping."

NASAofficials and researchers were aware of the difficulties that the teams for 1997'sPathfinder mission and the 2003 Mars Exploration Rover missions had when theytried living on Mars time. Phoenix principal investigator Peter Smith spokewith one of Barger's colleagues about coming to help his scientists adjust totheir demanding schedule, and NASA agreed to fund the study.


Barger andher team are intensely monitoring and working with the Phoenix team members in Tucson, Ariz.,, who all volunteered for the study. The medical team is providing the Phoenix crew with ways to adjust to their extreme schedule (Madsen's blue light box, forexample), as well as tracking the effects that living on Mars time has on them.

Each studyparticipant wears an "actigraph" watch that monitors his or her motion(people move less when they sleep) as well as their exposure to light, thatessential circadian cue. They also complete computer game-like reaction timetests before and after each shift. They use a scale on a computer to describetheir mood (tired people can often be grumpy) and to test their memory whilethey're on duty. The Harvard team is also measuring levels of a metabolite ofmelatonin in samples of participants' urine.

Becausemelatonin responds directly to the circadian clock, measuring its levels"tells us what time the clock is on, if you will," Barger explained,letting the researchers know whether or not the Phoenix team members wereadjusting to their schedule.

The lightboxes given to the participants help regulate their circadian clocks, givingthem the lightcues they miss on their shifting schedule.

"Normallywhen you're just living here on Earth, you have a 24-hour light-dark cycle, andyour clock gets reset every day," Barger explained. "When you areliving on a Mars day, your clock would have to be lengthened every day by abouta half hour. We know that bright light [particularly at the blue end ofthe spectrum] in the evening will help lengthen the day, so we've given themthis light box."

The Harvardteam is also providing Phoenix crew members with simple tips for dealing withfatigue, including drinking small cups of coffee throughout the day, instead ofa Venti mocha right before their shift; taking naps if their head startsbobbing at the computer; getting a full night's sleep and staying on Mars timeeven on days off.

How tolive on Mars time

Madsen, ascientist from the University of Copenhagen who works with the lander's roboticarm camera, says Mars time actually hasn't been too hard for him. As one of sixDanes temporarily living and working together while they're in Tucson for Phoenix's three-monthprimary mission, he says the camaraderie has helped him deal with thecontinually shifting schedule.

"Wetry to live like a family, and get up together in the morning, have breakfasttogether. And we keep each other on a tight schedule," he told

TroyHudson, a NASA Jet Propulsion Laboratory engineer with the lander's Microscopy,Electrochemistry and Conductivity Analyzer, has also had little trouble keepingon Mars time, clearly reveling in the experience.

"Personally,I rather enjoyed living on a Mars schedule, both for its, just, fundamentalunusualness, and of course it has made working with the spacecraft easy,"he said, though maintaining his pre-work gym routine when he was waking up at 2a.m. was a challenge.

Hudson, whois applying to be an astronaut, said that sitting in front of one of thebrilliant blue LED light boxes took some getting used to, though he grewaccustomed to it within a week or two.

Madsenagreed. Even though everyone walks around with a bloodless pallor, he thinksthat "it's doing its job producing something that is similar, more or lesssimilar to daylight, which helps us staying awake."

Noteveryone has found the experience as easy as Madsen and Hudson.

Nightowls vs. early risers

DeborahBass, a project scientist on the mission, says that the shift work can beharder for early risers like her than for night owls. "I like mornings. Sodoing this night work for me is extremely difficult," she said, adding:"I also really thrive on routine. So for me, this is also exceptionallychallenging."

Madsen didnote that sometimes he didn't sleep through the night and would be tired thenext day at work. In these cases he would take a brief snooze in nap roomsprovided to the scientists. "Just 10-20 minutes, you're just as newagain," he said. Hudson has never used the nap rooms, he said, though heacknowledged that "occasionally I have felt that tired."

Bass alsolived on Mars time during the MERprimary missions and monitored the effects of the schedule on the MER teamfor NASA, and said that the Phoenix team is experiencing some of the samedifficulties.

For peoplewho live in Tucson, where mission operations are based, the stress of living onMars time can actually be greater because staffers try to interact with theirfamilies on their days off. They may try to switch back-and-forth from Marstime, making the adjustment for their body harder. If they stayed on Mars time,they wouldn't be able to interact with their families as much. Crew memberscoming from other institutions and living temporarily in Tucson don't have thesame pressure to interact with their families, Bass said.

Madsen andhis Danish colleagues, for example, mostly email with their families, onlyseeing them on week-long trips back to Denmark ? switching back to Earth timeis a little easier for longer periods like this, they said.

Sociallife suffers

Bass andother mission scientists also said that it was difficult to interact withsociety on the rotating Mars schedule ? the options for socializing are slim ifyou're getting off of work at 3 or 4 a.m. Errands and laundry can't be done inthe middle of the night either.

"Soeven on your days off, you may not be really getting absorbed back into yournormal life," Bass said. "Life is hard to maintain."

Along thoselines, Madsen told a story of an encounter during an early morning hiking tripwith his colleagues that shows the disconnect the scientists can feel with theoutside world. Some passing hikers on the trail said, "Good morning."Madsen and his companions had to stop and think for a moment before replying "Goodmorning," because to them, it was almost bed-time.

On thewhole, Bass said that the reaction to living on Mars time is "veryindividually driven." Some, like Hudson, thrived on the schedule; others,like Bass, have struggled with it (Bass says the experience has given her moreappreciation for the schedule her husband works as an ER doctor).

Overallthough, Bass thinks the team is doing well and credits their drive and passionfor the mission, a once-in-a-career opportunity for many of them, for much ofthis.

"Theteam is extremely dedicated; the team has no intention of letting up, and theyabsolutely, again, they feel extremely privileged to have this opportunity towork on this Mars lander," she said.

Madsenagreed that the focus on the mission helped the team to almost ignore theEarth-bound schedule of the city around them. "We live kind of in our ownworld, because everything that is important to us takes place on Mars," hesaid.


Even thosewho have thrived on the Martian schedule must eventually come back down toEarth. The fatigue shown by the members of the Pathfinder and MER missions atthe end of a few months shows that "the team [only] seems to be able to dothis for a limited period of time," Bass said.

"Ithink that in the beginning, right after landing, the enthusiasm was at anabsolutely fever pitch. Adrenaline was coursing through the team for quite abit of time," as the first images came in and the components of the landerwere moved for the first time, she added.

Buteventually as the weeks wear on, and the mission moves forward, "there areless dramatic surprises, and less anticipation of a particular event," Hudson said. The number of applause-worthy events starts to become more spaced out.

Eventually,"one realizes that this is also one's life, that one needs to be able tosleep and eat and interact with family," Bass said.

Phoenix's primary mission comes to a close atthe end of August, and the team was set to return to Earth time for anypossible extendedmission. They'll actually make the switch earlier than expected, on Aug. 1.

The decisionto switch earlier was made because right now the team's Mars time schedulecoincides with local daytime, making the switch easier, according to Phoenix robotic arm co-investigator Ray Arvidson of Washington University in St. Louis. The team has become efficient enough now to make command decisions during theday, regardless of what time it is for the Phoenix lander, he added.

Bargerplans to publish results from her data collected during the two months that the Phoenix team has lived on Mars time sometime in 2009, and says they couldhelp inform whether futuremissions will live on Mars time.

However, asthe switch date draws near, neither Madsen nor Hudson is concerned about comingback down to Earth.

Hudson said he wouldn't mind staying onMars time for longer, but that it will be nice to have the chance to hang outwith friends who live in Tucson without first having to check and see if he'llbe asleep.

Madsenagreed: "I don't think [living on Mars time] has been a big deal, but in away it's nice to know that when you are [on Earth time], to know that you'll beon the schedule of Tucson local," he said. The switch back will beespecially nice for him, he added, as he will be taking two weeks off toexplore the area when his wife comes to visit, since he has mostly only seen Tucson and the mountains that surround it in the middle of the night.

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Andrea Thompson

Andrea Thompson is an associate editor at Scientific American, where she covers sustainability, energy and the environment. Prior to that, she was a senior writer covering climate science at Climate Central and a reporter and editor at Live Science, where she primarily covered Earth science and the environment. She holds a graduate degree in science health and environmental reporting from New York University, as well as a bachelor of science and and masters of science in atmospheric chemistry from the Georgia Institute of Technology.