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June 28th, 2024
Meteoroid impact detected by NASA’s InSight lander on Mars. The image was taken by NASA’s Mars Reconnaissance Orbiter using its High-Resolution Imaging Science Experiment (HiRISE) camera.
Image credit: NASA/JPL-Caltech/University of Arizona
New research points to Mars being on the receiving end of basketball-size meteorites – on a near daily basis.
An international research group, co-lead by ETH Zurich and Imperial College London, have derived the first estimate of global meteorite impacts on Mars using seismic data.
According to the new work, between 280 to 360 meteorites strike the Red Planet each year. The result is the formation of impact craters greater than 26 feet (8 meters across.
“This rate was about five times higher than the number estimated from orbital imagery alone. Aligned with orbital imagery, our findings demonstrate that seismology is an excellent tool for measuring impact rates,” explains Géraldine Zenhäusern of ETH Zurich who co-led the study.
Recorded very high frequency (VF) events, sorted by distance, plotted from 120 seconds before to 1,100 seconds after the event.
Image credit: Géraldine Zenhäusern, et al.
Seismic “chirp”
Using data from the seismometer deployed during the now non-functioning NASA InSight lander on Mars, the research team found that 6 seismic events belong to a much larger group of marsquakes, so called very high frequency (VF) events.
Their research quest began in December 2021, a year before accumulated dust on the InSight’s solar panels put an end to its mission.
Co-lead of the research, Natalia Wójcicka of the Imperial College London adds: “We estimated crater diameters from the magnitude of all the VF-marsquakes and their distances, then used it to calculate how many craters formed around the InSight lander over the course of a year. We then extrapolated this data to estimate the number of impacts that happen annually on the whole surface of Mars.”
This image shows InSight’s domed Wind and Thermal Shield, which covers the Seismic Experiment for Interior Structure (SEIS) seismometer.
Image credit: NASA/JPL-Caltech
New data shows that a crater 26-feet (8-meters) in diameter is formed somewhere on the surface of Mars nearly every day. A crater 98-feet (30-meters) happens about once a month.
Safety of robotic, human explorers
The research team, in an ETH Zurich statements, explains that, since hypervelocity impacts cause blast zones that are easily 100 times larger in diameter than the crater, “knowing the exact number of impacts is important for the safety of robotic, but also future human missions to the Red Planet.”
As for follow-up work, Zenhäusern and Wójcicka, say the next steps in advancing this research involve the use of machine learning technologies to aid researchers in identifying further craters in satellite images and identifying seismic events in the data.
Artist’s concept depicts astronauts and human habitats on Mars. NASA’s Mars Perseverance robot carries an oxygen-generating unit, viewed as a precursor for technologies that could make Mars safer and easier to explore for humans.
Image credit: NASA
Key findings
In summary form, for the first time, researchers have used seismic data to estimate a global meteorite impact rate showing meteoroids the size of a basketball impact Mars on a near daily basis.
Impact-generated seismic signals show meteorite impacts to be five-times more abundant than previously thought.
Seismic data offers a new tool in addition to observational data for calculating meteorite impact rates and planning future Mars missions.
To access their research paper just out in Nature Astronomy – “An estimate of the impact rate on Mars from statistics of very-high-frequency marsquakes” – go to:
Posted in Space News
