Image via DepositPhotos

Scientists at the U.S. National Institute of Standards and Technology (NIST) have calculated how time passes on Mars compared with Earth, adding detail to how timekeeping would need to work beyond Earth’s orbit.

The study, published in The Astronomical Journal, found that clocks on Mars run an average of 477 microseconds, or millionths of a second, faster per day than clocks on Earth. A microsecond is one millionth of a second, a very small unit used in precise scientific timing systems such as atomic clocks, which measure time using consistent atomic behavior.

This difference is not constant. Because Mars moves around the Sun in a non-circular path (an eccentric orbit, meaning its distance from the Sun changes over time instead of staying fixed) and is affected by gravity from other bodies, the daily difference can vary by as much as 226 microseconds over a Martian year.

The study also identifies smaller repeating changes of about 40 microseconds per day linked to synodic cycles (repeating periods that describe how planets line up with each other as they orbit the Sun from different positions). These longer patterns affect how time differences slowly rise and fall.