Mars Is Spinning Faster — Thanks to NASA’s InSight Mission
New data from NASA’s now-retired InSight lander reveals a surprising twist: Mars is gradually speeding up its rotation, shortening the Martian day by a tiny amount — about a fraction of a millisecond per year.
What's causing this?
Scientists are still investigating, but possible explanations include mass shifts at the polar ice caps or changes deep within the planet’s interior. Unlike Earth, which slows down due to the Moon’s influence on our oceans, Mars has no oceans — hinting at a completely different mechanism.
These insights come from InSight’s RISE (Rotation and Interior Structure Experiment), which tracked subtle changes in radio signals between Mars and NASA’s Deep Space Network over 900 Martian days. The variations helped scientists measure the planet’s spin with extraordinary precision.
More than just spin:
The same data also refined our understanding of Mars’ core, confirming it has a large radius of about 1,835 km and a density between 5.9 and 6.3 g/cm³. Interestingly, the planet’s nutation (wobble) suggests that its core has uneven density, raising new questions about its internal structure.
Why it matters:
Though InSight’s mission ended in December 2022, its legacy lives on. The RISE experiment is considered historic, continuing to deepen our understanding of the Red Planet and its hidden depths.
Published in: Nature (2023)
Paper: Sébastien Le Maistre et al., “Spin state and deep interior structure of Mars from InSight radio tracking”
Mars Is Spinning Faster — Thanks to NASA’s InSight Mission
New data from NASA’s now-retired InSight lander reveals a surprising twist: Mars is gradually speeding up its rotation, shortening the Martian day by a tiny amount — about a fraction of a millisecond per year.
What's causing this?
Scientists are still investigating, but possible explanations include mass shifts at the polar ice caps or changes deep within the planet’s interior. Unlike Earth, which slows down due to the Moon’s influence on our oceans, Mars has no oceans — hinting at a completely different mechanism.
These insights come from InSight’s RISE (Rotation and Interior Structure Experiment), which tracked subtle changes in radio signals between Mars and NASA’s Deep Space Network over 900 Martian days. The variations helped scientists measure the planet’s spin with extraordinary precision.
More than just spin:
The same data also refined our understanding of Mars’ core, confirming it has a large radius of about 1,835 km and a density between 5.9 and 6.3 g/cm³. Interestingly, the planet’s nutation (wobble) suggests that its core has uneven density, raising new questions about its internal structure.
Why it matters:
Though InSight’s mission ended in December 2022, its legacy lives on. The RISE experiment is considered historic, continuing to deepen our understanding of the Red Planet and its hidden depths.
Published in: Nature (2023)
Paper: Sébastien Le Maistre et al., “Spin state and deep interior structure of Mars from InSight radio tracking”
