A recent study published in Nature Astronomy has revealed that Mars is bombarded by hundreds of meteorites every year, a rate five times higher than previously thought. The study was conducted by an international team led by researchers from the Swiss Federal Institute of Technology Zurich and Imperial College London.
The researchers used the SEIS seismograph instrument dropped by the NASA spacecraft InSight on Mars in 2018 to listen to the impacts of meteorites on the planet. They discovered that Mars is hit by between 280 and 360 meteorites each year, creating craters at least eight meters in diameter. This rate was found to be much higher than previous estimates based on orbital images alone due to the difficulty of identifying new craters on Mars, especially in areas prone to sandstorms.
Previous estimates of the impact frequency on Mars were based on models that combined observations of meteorite craters on the Moon with surface images of Mars taken by orbiting probes. These models were adjusted to account for the differences in size and atmosphere between Mars and the Moon. However, these methods had limitations as they could not provide a comprehensive understanding of the frequency and location of impacts on Mars.
Using seismic data and acoustic waves generated by the impacts, the team was able to determine the number of craters created by meteorite impacts. This groundbreaking study provides valuable information for planning future missions to Mars and sheds light on the impact frequency on the red planet. Every month, on average, a meteorite hits Mars and creates a crater at least 30 meters in diameter.
