When you first see a Martian sunset on a NASA feed, it really gets to you. The sky goes from butterscotch to a cold blue halo around the Sun, and a robot you will never meet quietly counts the seconds until the light goes out.
When the sun goes down on Earth, it’s just sunset. It’s a scientific stopwatch on Mars.
Engineers in mission control have two clocks on their screens. One ticks off Earth seconds, and the other moves forward in Martian time, a “sol” that doesn’t fit into our neat 24-hour box. They joke about being “jet-lagged by a planet,” but the math behind their tiredness is very hard and exact.
Einstein said that motion and gravity would change time. Mars has made that vague idea a daily, stubborn fact.
Einstein’s theory comes true on Mars: time really does “run off” there.
There are 24 hours, 39 minutes, and 35 seconds in a Martian day. That looks harmless on paper, just a line in a mission brief.
It’s a slow, grinding change that pulls you out of sync with your own planet when you get up close. NASA teams working on Mars rovers talk about “living on Mars time,” which means going to bed at 6 a.m., waking up at noon, and eating lunch in the dark. Every sol, they lose 39 minutes of their schedule.
Their day has moved forward almost five hours compared to a normal day after a week.
Their body clocks are turned upside down after a month.
Time on Mars isn’t just a fun fact; it’s a test of how you live.
The rovers themselves live this distortion in a more real way.
Perseverance’s internal clock doesn’t just follow Earth hours; it’s set to local Martian solar time so it can wake up with the light, work while its instruments are warm, and sleep through the deadly cold.
Now missions are getting even weirder.
A recent effort to sync data between orbiters, landers, and Earth showed a measurable drift that is in line with what Einstein said: time moves at a slightly different rate on Mars because of its weaker gravity and different orbital speed.
We already fix this on GPS satellites that go around the Earth.
These changes are no longer just ideas on Mars.
If you don’t pay attention to them, your navigation can be off by meters, then kilometres.
After years of exploration, that “tiny” difference can mean the difference between landing in a safe plain or a deadly crater.
According to Einstein’s general relativity, speed and gravity change the flow of time.
Time goes a little slower when you are near a big object.
Same thing, go faster.
Mars has less mass and a weaker gravitational field than Earth does.
The clocks on Mars move a little faster than the clocks on Earth that are the same.
The difference is so small that you can’t see it from one day to the next, but mission planners don’t think in days; they think in decades.
This difference is no longer just a footnote in a physics paper now that we’re planning long-term human missions.
It affects trajectory design, landing windows, orbital rendezvous, and even how often astronauts talk to their families.*Time itself has become another hostile environment to deal with, like radiation or dust.*
Making a future where astronauts live between two clocks
The agencies are already making changes before the first crewed mission starts.
International space organisations came up with the idea of a “Mars time standard,” which would be a single, agreed-upon reference for Martian clocks, like Coordinated Universal Time (UTC) on Earth.
It sounds like a lot of red tape, but it’s a way to stay alive.
Future bases, rovers, drones, and orbiters will need to agree on a common second, noon, and calendar of sols.
Otherwise, a single wrong timestamp could mess up navigation data or make it harder to respond to an emergency.
Engineers are already testing software that automatically converts between Earth time and Mars time, adding relativistic corrections to every piece of data.
For them, “What time is it?” is becoming a very important question.
The mental side is just as hard.
We’ve all been there: that moment when a long flight messes up your sense of day and night and your brain feels like wet cardboard.
Now, spread that out over 500 days on a base on Mars.
Do you run the habitat on Martian sols, where the days are longer and the routines change, or do you keep a 24-hour Earth-like rhythm and let “outside time” be something else?
Both choices hurt.
Astronauts already practise changing their sleep schedules on analogue missions and in underwater habitats.
They use blue- and red-tinged LEDs to slowly pull the body clock to where it needs to be for the mission, like the slow dawns on Mars.
Let’s be honest: no one really does this every day without feeling a change in their mood.
Researchers in health are quietly worried about being on a 24h39 schedule for a long time.
Your body’s internal clock is set to the cycle of light and dark on Earth and its gravity.
If you pull it out of sync, you could have trouble sleeping, slower reaction times, and small cognitive slips at the worst possible times.
The first missions to Mars will need to keep their “time hygiene” very strict.
Like very strict good sleep habits, it has set wake windows, planned naps, meals at the right times, and even drugs that help the body clock.
Some teams want “hybrid time,” which means that crews on Earth use Earth time for inside work and Mars time for outside work, keeping track of two calendars at once.
Einstein sneaks back in during that juggling act.
As missions get longer, his equations about how clocks move differently in different gravitational wells become part of medical protocol, not just maths for satellites.
In a way, future settlers on Mars won’t just be people who moved there from Earth.
They will be people who live in the past.
One European mission planner told me during a late Zoom call, “Time is not a constant background on Mars.”
“Like fuel or oxygen, it’s a variable we have to work around. If you don’t pay attention to it, the mission will fail quietly.
Changing mission software
As a default, every navigation, communication, and planning tool should have built-in Mars time and relativistic corrections, not as an afterthought.
Keeping people’s sleep patterns safe
Smart lighting, scheduled “Earth-time days,” and medical monitoring will help crews ride the 24h39 wave without breaking down.
Making a clock for everyone on Mars
A common standard will let hardware from different countries work together on the same timeline, from self-driving drones to homes built underground.
Teaching relativity as a useful skill
Pilots and mission controllers will look at Einstein’s equations like pilots look at weather reports: they are dry on paper but very real in the cockpit.
Planning for time drift on long missions
Multi-year exploration will need to take into account small time differences that can lead to big mistakes in navigation and scheduling.
When you start to think about time on Mars, it won’t let you go.
If we get that far, kids born there will learn that their birthday lasts 39 minutes longer than yours.
Their work week, parties, and “one more episode” at night all lasted longer and were a little different from ours.
Instead of continents, time zones will follow craters and canyons.
A phone call from Paris to a dome in Jezero Crater at night will always feel a little off, like someone’s clock is lying.
They will both be correct, but they will still be out of sync.
There is a quiet, unsettling thought behind the engineering: as we spread out across the Solar System, our shared sense of time will slowly break down.
Relativity goes from the blackboard to the table.
What seems like one person’s story right now could turn into two separate timelines that only match up on paper over the course of hundreds of years.
| Key point | Detail | Value for the reader |
|---|---|---|
| Mars days are longer | Each sol lasts 24h 39m 35s, creating schedule drift for missions | Helps you grasp why Mars missions talk about “living on Mars time” |
| Relativity is operational | Weaker Martian gravity and different motion slightly speed up local clocks | Shows that Einstein’s theory directly shapes navigation and communication |
| Human adaptation is key | Lighting, routines, and a shared Mars time standard are being designed | Gives a concrete sense of how astronauts — and one day settlers — might live |
FAQ:
- Does time really move at a different speed on Mars?
- Is the longer day on Mars the same as relativity?
- Will astronauts be able to feel this time difference?
- How do missions deal with time on Mars right now?
- Will people who move to Mars in the future use a different calendar?
