A new study has revealed that the frequency of space rocks hitting Mars is higher than previously thought, revealing two of the most powerful collisions with the Red Planet that scientists have ever seen. The Mars InSight lander continues to advance our understanding of Mars with data that reveals a higher-than-expected rate of asteroid impacts, albeit inactive. This information, obtained from analysis of both seismic and orbital imagery, suggests that current models of the surfaces of Mars and other planets in the Solar System need to be updated.

New information from Mars: Increasing meteorite impacts

NASA’s Mars InSight Lander may be resting on the Red Planet, but the rover’s data is still leading to seismic discoveries back on Earth.

In one of the latest studies using data from spacecraft, an international team of scientists led by a researcher from Brown University has found that Mars may be bombarded by space rocks more frequently than previously thought. According to a study published in Science DevelopmentsDepending on the size of the meteors, the impact speed could be two to ten times higher than previously estimated.

“It’s possible that Mars is more geologically active than we thought, with implications for the age and evolution of the planet’s surface,” said lead researcher Ingrid Daubar, associate professor (research) of Earth, Environmental and Planetary Sciences at Brown. “Our results are based on the small number of samples we have, but an estimate of the current impact rate suggests that the planet is impacted much more frequently than we can see using images alone.”

Advances in Mars geology and crater exploration

As part of the study, the team used InSight’s highly sensitive onboard seismometer to identify eight new impact craters from meteoroids that had not previously been seen from orbit. The frequency of these cosmic impacts challenges current understandings of how frequently meteoroids collide with the Martian surface and suggests the need to revise current models of cratering on Mars to specifically include higher-frequency impacts from smaller meteoroids. These findings could ultimately change current understanding of the Martian surface and the history of impacts not only with Mars but also with other planets as small meteor impacts continue to shape it.

Rethinking models of the planet’s surface

“This will require us to rethink some of the models that the scientific community uses to estimate the age of planetary surfaces in the Solar System,” Daubar said.

The six craters the researchers found were close to where the InSight geostationary lander had crashed. The two distant impacts they discovered from the data were the largest scientists have ever detected, even after decades of orbital observations. The larger impacts, each leaving a crater roughly the size of a football field, occurred just 97 days apart, underscoring the higher frequency of such geological events.

“We expect this kind of large-scale impact to happen maybe once every few decades, maybe even once in a lifetime, but here we have two of them, separated by a little over 90 days,” Daubar said. “It could be a crazy coincidence, but the chances of it being just a coincidence are very, very low. It’s more likely that these two big impacts are related, or that the impact rate on Mars is much higher than we thought.”

Improved shock detection methods

The InSight mission, led by NASA’s Jet Propulsion Laboratory (JPL) in Southern California, operated from November 2018 to December 2022. One of its main goals was to measure the planet’s seismological vibrations. Recent impacts with Mars have previously been detected using before-and-after images taken by cameras in orbit around the planet. The seismometer provides a new tool to find and detect these impacts, many of which would otherwise be missed.

“Planetary collisions happen all the time, all over the solar system,” Daubar said. “We want to study it on Mars because we can compare what’s happening on Mars to what’s happening on Earth. It’s important to understand our solar system, what’s in it, and what the population of objects that are colliding in our solar system looks like, both as a threat to Earth and historically to other planets.”

The rates are also important for assessing potential hazards posed by exposure for future research missions, where NASA sends rovers or even human missions into space.

To determine when and where the impacts occurred on Mars, Daubar and his research team analyzed seismic signals from InSight and then compared that seismic data with images taken by NASA’s Mars Reconnaissance Orbiter.

The team visually confirmed that eight events were new craters by examining before and after images. This dual approach, using seismic data and orbital imaging, allowed them to confirm that the seismic signals were caused by shocks and cross-check their findings to ensure accuracy.

Final understanding of Mars’ seismic activity

The InSight lander collected seismic data during its descent until its solar panels were so covered in dust that they could no longer generate electricity.

“This latest paper is proof that even though InSight is no longer operational, its data continues to help us understand Mars,” said Mark Penning, InSight project scientist at JPL, who was not involved in the research. “We’re excited to see what else is hidden in the mission’s seismic readings.”

The current study by Daubar and his research team is related to the following companion article: Nature Communication This uses even more data from InSight to look at all the high-frequency seismic events detected by the lander. A companion paper suggests that all of these events were caused by impacts, and finds that the final estimated velocity is consistent with an independent calculation by researchers from Daubar’s team, further strengthening each group’s conclusions.

“It’s possible that many of the events that InSight recorded during its mission were actually impacts,” Daubar said. “The next steps are to do more detailed orbital searches using machine learning techniques to try to confirm this. If we can confirm more shocks, we may also be able to find other seismic signals caused by the shocks.”