Marte is reducing the length of its days due to the acceleration of its turnover rate, according to data obtained by the InSight module of the NASA before the end of his mission last December.
In addition, the scientists in charge of said laboratory that is located on the surface of the Red planet have made more precise measurements of the rotation of Mars, detecting for the first time that the planet wobbles due to the “splashing” of its molten metal core.
To track the rate of spin of the planet, the study authors have relied on a radio transponder and antennae collectively called Interior Structure and Rotation Experiment, or RISE. They found that the planet’s rotation is accelerating by about 4 milliarcseconds per year, which corresponds to a reduction in the length of the Martian day by a fraction of a millisecond per year.
It’s a subtle acceleration, and scientists aren’t entirely sure what’s causing it. But they have some ideas, including the accumulation of ice in the polar caps or the post-glacial rebound, where land masses rise after being buried by ice. The change in a planet’s mass can cause it to speed up a bit like an ice skater spinning with its arms outstretched and then retracting them, NASA explains.
The study authors have also used the RISE data to measure the wobble of Mars, called its nutation, due to the splash in its liquid core. The measurement allows scientists to determine the size of the nucleus: according to the RISE data, the nucleus has a radius of approximately 1,835 kilometers.