The difference is minimal, almost imperceptible, but very real. The planet Mars is spinning faster and faster, as revealed by data collected by NASA’s “InSight” lander. These data collected over 900 days have allowed astronomers to note an acceleration of about 4 milliarcseconds per year. A milliarcsecond is an astronomical measurement.
What this hard-to-find anomaly means to ordinary mortals is that the length of a day on the red planet is constantly getting shorter. The change is minimal. There, a day lasts about the same as on Earth, with only 40 minutes longer. The length of the day is shrinking by about a fraction of a millisecond per year.
As CNN points out, researchers cannot precisely identify the causes of this acceleration. Two hypotheses are tentatively proposed: it could be due to the accumulation of ice at the Martian poles or to the elevation of the continental masses after being covered with ice. However, when the mass of a planet moves, the rotation can speed up. Which is, a priori, nothing to worry about.
A difficult variation to observe
The researchers behind this discovery had to compete in wits to pull it off. Ils ont dû observe des variations de frequences dans des signaux radios émis depuis la planete, et measurer la variation de ceux-ci par le décalage Doppler, le même principe qui fait varier la tonalité d’une sirène de police en fonction de la distance de this.
“What we are looking for are variations of a few tens of centimeters during a Martian year,” said Sébastien Le Maistre, lead author of the study and a researcher at the Royal Observatory of Belgium, in a statement. “It takes a lot of time and data to accumulate before you can observe these variations.
The results of this “historic” study were reported on June 14, 2023 in an article published in the scientific journal Nature. The Insight device ran out of power and shut down in December 2022, but the data collected during its four years of life provided scientists with extremely important information and helped them better understand the red star. Other discoveries could still be hidden there.
Source: BFM TV
