Physicists at the National Institute of Standards and Technology (NIST) in the United States have, for the first time, calculated how much faster clocks run on the surface of Mars compared to Earth. On average, a Martian day runs ahead by 477 microseconds, but throughout a Martian year this value fluctuates within plus or minus 226 microseconds due to the planet’s elliptical orbit and the gravitational influence of other planets. The results were published in The Astronomical Journal.

Why Time Runs Faster on Mars

According to Einstein’s general theory of relativity, the passage of time depends on the strength of the gravitational field: the weaker the field, the faster clocks tick. Gravity on Mars is only 38 percent of Earth’s (3.72 meters per second squared versus 9.81), so time there is objectively faster. Scientists selected a reference point — a notional zero altitude on the Martian surface, analogous to sea level on Earth — and performed calculations accounting for all gravitational perturbations.

“This was far more difficult than doing the same for the Moon. Mars is part of a nonlinear four-body system, and such calculations are incredibly demanding,” said one of the study’s authors, Bijunander Patla.

For comparison: on the Moon, clocks run steadily faster by 56 microseconds per day, but on Mars the difference is not only larger, it is also variable.

Why Such Precision Is Needed

The 477-microsecond difference may seem insignificant, but in the era of interplanetary missions it is critical. Modern 5G communication systems require synchronization accurate to 0.1 microseconds, and future Martian networks will need even greater precision. Signals between Earth and Mars take from 4 to 24 minutes to travel, and even the slightest desynchronization of clocks can cause cumulative errors in navigation, data transmission, and rover operation.

Precise calculations will make it possible to create a unified “solar system” time standard that can operate consistently on Earth, the Moon, Mars, and beyond — without the need for constant recalculation of delays and gravitational corrections.

In Short

Time on Mars flows on average 477 microseconds faster than on Earth, with seasonal variations of plus or minus 226 microseconds. This is the first precise gravitational-relativistic time calculation for the Red Planet. The results will form the basis of a future interplanetary time system and reliable communications in the era of crewed missions to Mars.