Mars continues to surprise us, and recent findings from the InSight lander have given us the most precise measurement yet of the red planet’s rotation. Here’s what you need to know about these groundbreaking results.
The Discovery of Mars’ Accelerating Spin
The data from the InSight lander revealed that Mars’ rotation is speeding up slightly each year, with an acceleration of about 4 milliarcseconds annually. This means the length of a Martian day is shortening by a tiny fraction of a millisecond every Martian year. While this might seem insignificant, it points to complex internal and possibly climatic changes on Mars.

Potential Causes of This Phenomenon
- Accumulating Material at the Poles: One hypothesis is that material, possibly ice, is building up at the polar caps, affecting the planet’s rotation.
- Internal Dynamics: The other major theory involves changes in the distribution of Mars’ internal mass, possibly linked to its core or geological activity.
How Was This Measured?
The key tool here wasn’t seismic equipment, but radio communications. InSight’s Rotation and Interior Structure Experiment (RISE) used signals sent between the lander and NASA’s Deep Space Network to detect tiny variations in Mars’ rotation.

Implications of the Findings
- Understanding Mars’ Interior: The RISE data not only refined our measurements of Mars’ core but also revealed variations in density within the core itself.
- Comparisons to Earth: Unlike Earth, where the moon slows our rotation, Mars lacks such tidal influences, suggesting unique internal processes.
Why Is This Important?
These findings help scientists understand the geodynamic processes of Mars, offering clues about its formation and evolution, which is crucial for future missions and possibly even colonization.
What Comes Next?
Researchers plan to continue analyzing the data from InSight to explore the reasons behind Mars’ accelerating spin and to gain more insights into its geological activity.
The research has been published in Nature.