A new study published December 1 in The Astronomical Journal has revealed a surprising truth about the way time passes on Mars. The research confirms that clocks on the red planet tick faster than clocks on Earth, and the reasons trace back to Einstein’s general relativity. The findings reshape how scientists think about interplanetary navigation, future Mars missions, and the basic physics of time in our solar system.
According to the reference study, time on Mars runs faster because the planet has weaker gravity than Earth. General relativity tells us that stronger gravity slows time, while weaker gravity allows it to run ahead. Since Mars is smaller and less massive, the pull of gravity on its surface is weaker, letting time move slightly faster there.
But gravity alone is not the whole story. The study shows that Mars’ highly eccentric orbit adds another layer of complexity. As Mars moves closer to or farther from the sun, variations in the planet’s orbital speed and distance create measurable changes in how fast time passes. Lead author B. R. Patla noted that Mars’ changing distance from the sun “makes the variations in time larger,” showing how the planet’s orbital path helps shape the rhythm of time itself.
Over a typical 15.8 year Martian opposition cycle, the study finds that clocks on Mars advance an average of about 477 microseconds per day compared to Earth. The offset oscillates as the planets move around the sun, creating a repeating pattern that becomes especially important for missions that require millisecond precision.
These differences pose real challenges for future navigation systems on Mars. Just as Earth relies on GPS satellites that depend on flawless timing, crews and rovers on Mars will require similarly accurate systems. The presence of four major bodies in the mix, including the sun, Earth, the moon, and Mars, makes the calculations far more difficult. Patla described the problem as “more challenging than I initially thought,” highlighting how sensitive space navigation is to even tiny variations in time.
Co-author Neil Ashby emphasized that any future Martian navigation network must rely on relativity from the start. Without accounting for shifting clock rates, signals between landers, rovers, and orbiters could drift, creating navigation errors that grow with time.
Researchers say the study comes at the perfect moment. With renewed plans for lunar bases and the first human missions to Mars, scientists are beginning to build the systems needed for interplanetary travel. Understanding how time behaves on other worlds is a key step in turning science fiction into reality.