Mars Is Spinning Faster: NASA’s InSight Uncovers Surprising Acceleration

NASA’s InSight Mars lander detected a surprising acceleration in Mars’s rotation and a wobble in the planet caused by its molten core. This has provided unprecedented insights into the Martian core’s size, shape, and internal structure.

Scientists used an instrument on InSight called the Rotation and Interior Structure Experiment (RISE) to monitor Mars’s spin rate. They detected an acceleration in the planet’s rotation and measured its wobble, which allowed them to infer information about the core’s liquid movement.

The subtle acceleration is significant as it provides clues about the planet’s internal structure and potentially about phenomena like ice accumulating on the polar caps or post-glacial rebound. Understanding these aspects helps in revealing the dynamics of Mars’s geophysical changes.

RISE is part of InSight and employs advanced radio technology and antenna upgrades within NASA’s Deep Space Network on Earth. It reflects radio signals to look for tiny changes in frequency, providing data about five times more accurate than earlier missions like the Viking landers in the 1970s.

RISE data helped measure Mars’s wobble due to its liquid core’s movement, allowing scientists to estimate the core’s radius and providing details about its shape. This contributes to understanding the core’s size and density variations deep within the mantle.

JPL managed InSight for NASA’s Science Mission Directorate, and Lockheed Martin Space built the spacecraft. There were several European partners involved, including France’s Centre National d’Études Spatiales (CNES) and the German Aerospace Center (DLR).

Bruce Banerdt, who served as InSight’s principal investigator, marked this study as the final chapter in his role for the mission. He retired on August 1, after a 46-year career with JPL, reflecting on the results as making the decades of work worthwhile.