A new study led by a Brown researcher reveals the frequency of space rocks pummeling Mars is higher than previously estimated and detects two of the largest impacts ever seen by scientists on the Red Planet.
PROVIDENCE, R.I. [Brown University] - NASA's Mars InSight Lander may be resting on the Red Planet in retirement, but data from the robotic explorer is still leading to seismic discoveries on Earth.
In one of the latest studies using data from the spacecraft, an international team of scientists led by a Brown University researcher found that Mars may be getting bombarded by space rocks at more frequent rates than previously thought. Impact rates could be two to 10 times higher than previously estimated, depending on the size of the meteoroids, according to the study published in Science Advances.
"It's possible Mars is more geologically active than we thought, which holds implications for the age and evolution of the planet's surface," said lead researcher Ingrid Daubar, an associate professor (research) of Earth, environmental and planetary sciences at Brown. "Our results are based on a small number of examples available to us, but the estimate of the current impact rate suggests the planet is getting hit much more frequently than we can see using imaging alone."
As part of the study, the research team used InSight's highly sensitive onboard seismometer to identify eight new impact craters from meteoroids not previously seen from orbit. The frequency of these cosmic collisions challenges existing notions about how often meteoroids hit the Martian surface and suggests a need to revise current Martian cratering models to incorporate higher impact rates, especially from smaller meteoroids. The findings could ultimately reshape current understandings of the Martian surface - as batterings from small meteoroids continue to sculpt it - and the impact history of not just Mars, but other planets.
"This is going to require us to rethink some of the models the science community uses to estimate the age of planetary surfaces throughout the entire solar system," Daubar said.
Six of the craters the researchers detected were near the site where the stationary InSight lander set down. The two distant impacts they identified from the data were the two biggest impacts ever detected by scientists, even after decades of watching from orbit. The larger impacts, each leaving a crater roughly the size of a football field, came just 97 days apart, underscoring the higher frequency of these types of geological events.
"This size impact, we would expect to happen maybe once every couple of decades, maybe even once in a lifetime, but here we have two of them that are just over 90 days apart," Daubar said. "It could just be a crazy coincidence, but there's a really, really small likelihood that it's just coincidence. What's more likely is that either the two big impacts are related, or the impact rate is a lot higher for Mars than what we thought it was."
