NASA’s recent warning is shedding light on Mars’ core activity, providing the most accurate measurement of Mars’ rotation speed. This discovery has left scientists both surprised and intrigued.
Mars (Image: NASA).
While the InSight Mars lander has ceased operations, the data it collected during its time on the Martian surface has revealed that the planet’s rotation is accelerating by approximately 4 milliseconds per year. While this may seem like a very small amount of time, it translates to Mars’ days getting about 1/1,000 of a second shorter each day. The cause of this phenomenon, however, remains unexplained.
Nonetheless, this finding deepens our understanding of Mars and its evolutionary processes. Some hypotheses suggest that this is a long-term trend and a consequence of the planet’s internal dynamics.
Despite InSight running out of energy and ceasing its operations in December 2022, the four years’ worth of data it collected have significantly contributed to our understanding of Mars. Observations made about Mars’ core have opened entirely new doors for comprehending the planet. The seismic data provided by the lander not only revealed insights about Mars’ internal structure but also the composition of its liquid core and ongoing tectonic activity.
A self-captured image by the InSight lander in April 2022. The photo reveals its solar panels covered in dust. (Image: NASA/JPL-Caltech).
NASA, equipped with abundant and valuable data, continues to improve its instruments for more efficient data utilization. Satellite signals transmitted between Earth and Mars allow scientists to detect subtle changes in radio wave frequencies, enabling precise measurements of Mars’ rotation.
While Mars’ acceleration is minimal, it has been identified. This could be attributed to a redistribution of mass within the planet. Unlike Earth, which is experiencing a slowing rotation due to the tidal braking effect of the Moon on our oceans, Mars doesn’t have oceans. Therefore, something else is at play here. Scientists will further analyze to determine the cause behind Mars’ acceleration.
Illustration of Mars’ core structure based on seismic data. (Image: IPGP/David Ducros).
InSight has also assisted scientists in fine-tuning the measurement methods for detecting vibrations caused by fluid motion, providing more accurate results regarding Mars’ core. These measurements suggest that Mars’ core has a radius ranging from 1,780 to 1,830 kilometers, which is relatively large compared to the planet’s overall radius of 3,390 kilometers. Seismic analysis also indicates that the core’s density ranges from 6.2 to 6.3 grams per cubic centimeter.
The data provided by InSight aligns closely with these analyses, resulting in a core radius of 1,835 kilometers and a core density ranging from 5.9 to 6.3 grams per cubic centimeter. However, Mars’ core oscillations indicate that this density is not evenly distributed. Variations in density within the core will continue to be a point of focus for future research.
Astronomer Sebastien Le Maistre at the Royal Observatory of Belgium considers the experiments based on InSight’s data a historical endeavor. He says, “We’ve invested a lot of time and effort preparing for these experiments and have predicted these discoveries. However, this doesn’t mean that we won’t encounter significant surprises during our investigations, and there are still many more discoveries to be made to better understand Mars.”