Accurate readings of Mars’ rotation speed, courtesy of NASA’s InSight Martian probe, were higher than previously thought. These data are of great importance for studying the planet’s internal structure. Seismic measurements that provide information about the structure of Mars require more advanced robots or even humans. However, indirect seismic experiments, such as capturing echoes from Mars tremors and determining the planet’s rotation and wobble rates, allow us to hypothesize about its structure.
The Rotation and Interior Structure Experiment (RISE) antenna array was installed on the InSight probe to measure the rotation rate of Mars. Using NASA’s network of Earth-based antennas, the signal was sent to RISE and then analyzed for Doppler distortion. This allowed Mars’ deviations from a certain position in space to be determined. It required 600 days of observations and careful noise filtering to achieve a measurement accuracy that was less than 40 centimeters.
The results of the study, published in the journal Nature, showed that Mars is rotating faster than previously thought. Its rotation rate is increasing at 4.4 angular milliseconds per year, which is much slower than Earth’s rotation rate. This means that the length of daylight on Mars will shorten by a fraction of a millisecond every Martian year.
Measurements of Mars’ rotation rate and the wobble of its axis allowed scientists to draw conclusions about the size of the planet’s liquid core. They suggested that its size is between 1,790 and 1,850 kilometers. This value is important for understanding the overall structure of Mars, given that its radius is only 3,390 kilometers, about half the radius of Earth. Scientists also noted that the dynamics of rotation of the Red Planet may be influenced by the inhomogeneity of the density of its core.
Studies of Mars and its rotation are an important step in understanding this mysterious planet. Thanks to data from the InSight probe, we can better understand the internal structure of Mars and its evolution. This opens up new opportunities for further research and gives us more information about what processes are taking place on this planet.