New Mars Quakes Reveal Daily Meteorite Strikes
A new study estimates that up to 360 meteorites hit Mars each year, based on seismic data from the InSight mission.
An international team of researchers, led by scientists from ETH Zurich and Imperial College London, has used seismic data to estimate that between 280 and 360 meteorites strike Mars annually, creating craters larger than 8 meters in diameter. This finding, published in a recent study, is the first global estimate of meteorite impacts on Mars and highlights the power of seismology in measuring such events.
The research team analyzed data from the seismometer on NASA's InSight mission, identifying 6 previously known meteorite impacts and discovering that they belong to a larger group of high-frequency seismic events. These events, known as very high frequency (VF) quakes, occur much faster than typical tectonic quakes, with impacts generating seismic waves in just 0.2 seconds. By analyzing the seismic data, the team identified an additional 80 potential impact events.
The study began in 2021, before the InSight mission ended due to dust accumulation on its solar panels. During this time, the team detected a large seismic event that was later linked to a 150-meter-wide crater. By comparing seismic data with images from the Mars Reconnaissance Orbiter, they confirmed the presence of a second fresh crater. However, smaller impacts from basketball-sized meteoroids remained difficult to detect.
Compared to Earth, Mars has a much thinner atmosphere, making it more vulnerable to frequent and larger meteorite strikes. While about 17,000 meteorites fall to Earth annually, most disintegrate in the atmosphere. On Mars, however, the lack of a thick atmosphere means more meteorites reach the surface. Scientists had previously relied on orbital imagery and lunar impact models, but these were less effective for Mars due to its dynamic environment and sandstorms that obscure craters.
The researchers used the InSight seismometer to detect impacts and estimate the number of craters formed over a year. They found that an 8-meter crater forms nearly every day, while a 30-meter crater appears about once a month. These findings offer new insights into the geological history of Mars, as the number and size of craters can reveal the age of different regions on the planet's surface.
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