According to new research based on the data returned by NASA’s InSight mission, about 300 meteorites the size of basketballs hit Mars every year—a lot more than scientists had thought. Beyond their usefulness in explaining the frequency of meteorite impacts, the findings from seismic data acquired by InSight’s seismometer have introduced a new way to date planetary surfaces around the Solar System.
A study led by scientists from Imperial College London and ETH Zurich, working as part of NASA’s InSight mission, published today in Science, highlights how ‘marsquakes’ caused by meteorite impacts are more common on Mars than originally thought. It calculates that the annual impact rate could be between 280 and 360 meteorite events, including craters larger than eight meters in diameter and creating seismic perturbations throughout the surface of the planet.
As Dr. Natalia Wojcicka, a Research Associate at Imperial College London, says, this seismic data holds fantastic potential to further refine models of the geological timeline and evolution of Mars. The skill is equivalent to having a kind of “cosmic clock” that may, she hopes, unravel the history of the Red Planet and perhaps provide insight into other planetary surfaces within the Solar System.
In a paper published in the journal Nature Astronomy, scientists employed this rags-to-riches strategy to do something no one has tried before: use crater counts—age indicators developed from lunar models—to estimate planetary age. These models have to be tweaked for application on Mars because of factors such as interference from the atmosphere and the size and position of the planet in the Solar System.
Previous searches for new small craters on Mars, using telescopic images, returned fewer craters than expected. InSight’s seismometer, SEIS, however, detected a suite of distinct seismic signals that were clearly ‘very high-frequency’ marsquakes related to meteorite impacts. That is because these signals were marked by high-frequency waves and other seismic characteristics unique to them, which make tracing meteorite impacts easier than traditional visual surveys.
In particular, Professor Gareth Collins of Imperial College London believes that SEIS has been able to detect impacts, showing that seismic detection is generally much more accurate and frequently done than visual observation. This finding strongly underscores the fact that the instrument is crucial to further refining our understanding of Martian impact rates and geological processes.
The research team suggests, therefore, that future Mars missions should be equipped with smaller, more cost-effective seismometers in order to further enhance knowledge of Martian seismology and internal structure by increasing the data set of seismic signals and enabling more general investigations on meteorite impacts and planetary interiors.
Dr. Wojcicka pointed out the role of seismology in planetary science, pointing out its part in the unlocking of chemo-density planetary compositions and layering. On Earth, a global network permits robust insights into the inner dynamics of our planet. On Mars, with only one operational seismometer, there are difficulties that require broad deployment to understand geological and tectonic activity.
In a second study, also in Science Advances, that almost mirrors the team’s findings, the results prove the consistency and replicability of the conclusions by different methods. By combining seismic data from atmospheric signals with imagery from InSight, both studies obtain very similar impact rate estimates that increase confidence in these results within the scientific community.
Launched in 2018, NASA’s InSight introduces a new generation of missions strongly aimed at exploring the deep interior of Mars using leading-edge geophysical instruments. Along with SEIS, InSight comprises tools such as a heat flow probe and precision radio instruments designed to help in unraveling the detailed structure of Mars and provide comparative insight into Earth and other terrestrial planets.
InSight has thus newly redefined surface dynamics and impact processes on Mars with the most sophisticated seismic research performed to date. The SEIS-made discovery of meteorite impacts is the first of its kind to open new viewpoints on planetary exploration, underlining the role of Mars as a window to the early evolution of our System’s rocky planets. As future missions build on such gains, it sets the stage for deeper insights into Martian geophysics and the broader mysteries of our Solar System’s rocky planets.
The discovery of frequent meteorite impacts on Mars has an effect that is far from being a strictly geological curiosity. The capacity to date planetary surfaces by seismic data provides further insight not only into Mars but also prepares future missions that will want to explore and even possibly colonize the Red Planet. For example, knowledge in terms of precise rates and effects of impacts on the Martian terrain is critical for planning safe landing sites and evaluating environmental hazards for human missions.
The research points out a more general application of seismological techniques in planetary science: only by refining methodologies for the detection and analysis of seismic signals on Mars can similar studies on other celestial bodies, both inside and outside our Solar System, be set up. Therefore, this technique offers enormous potential for establishing geological histories of moons and planets and hence greatly enhancing our understanding of planetary formation and evolution in general.
These results could find practical applications even in the domains of terrestrial seismology and impact studies. For example, to design strategies for the monitoring of impact events and associated seismic activity on Earth, one could draw upon lessons learned from Mars seismology. Such cross-disciplinarity opens up new avenues not only for planetary research per se but also radically enhances our competence toward the assay of planetary hazards and amelioration of disaster preparedness right here on Earth.
Looking ahead, integration of sophisticated seismological instruments on the next sets of Mars missions is very key in developing our understanding of the global geological and tectonic processes on the planet. Emplacement of arrays of seismometers will further help researchers capture a more detailed picture of seismic activity and eventually characterize the interior structure of Mars. It is not only raising our scientific understanding but also setting a foundation for future exploration missions to explore the secrets of Mars and other celestial bodies within our Solar System.
Conclusion: NASA’s InSight mission, with its groundbreaking findings on Martian meteorite impacts, shows how seismology research transforms planetary science. As such, using seismic data to help decipher impact rates and geological histories will put scientists in the best position to track Mars’ evolution and hopefully define the future of Mars exploration, enabling humans to finally walk on, inhabit, and do much on the Red Planet. With new technology advancing and changes in missions, the scene is set for new discoveries to be made that shape and give a new view of our cosmos, refocusing humanity’s quest for planetary exploration.
Regarding the planetary evolution of Mars, meteorite impacts help to improve understanding with broader implications for astrobiology and the search for life elsewhere in the solar system. Such impact events may create habitats with peculiar geochemical conditions that could house microbial life. Understanding the frequency and distribution of meteorite impacts, the choice of areas on Mars where ancient life could have thrived, or where biosignatures could exist, would become important. It is knowledge that has opened up pathways for future missions with the objective of propelling our quest on unraveling issues underlying the origins of life in the universe by looking for signs of either past or present life on Mars.
In a nutshell, NASA’s InSight made parallel the seismological data in opening up the frequency of meteorite impacts on Mars. Such a discovery improves our understanding of planetary geology and surface processes and aids strategic planning for future missions of exploration. With continued exploration and analysis of seismic activity at Mars, scientists are well on their way to uncover more secrets of the Red Planet, deepening our understanding of its past, present, and potential for life.