A global team of scientists have announced the results of an unprecedented collaboration to search for the source of the largest ever seismic event recorded on Mars. The study, led by the University of Oxford, rules out a meteorite impact, suggesting instead that the quake was the result of enormous tectonic forces within Mars’ crust.
The quake, which had a magnitude of 4.7 and caused vibrations to reverberate through the planet for at least six hours, was recorded by NASA’s InSight lander on May 4 2022. Because its seismic signal was similar to previous quakes known to be caused by meteoroid impacts, the team believed that this event (dubbed ‘S1222a’) might have been caused by an impact as well, and launched an international search for a fresh crater.
Although Mars is smaller than Earth, it has a similar land surface area because it has no oceans. In order to survey this huge amount of ground — 144 million km2 — study lead Dr Benjamin Fernando of the University of Oxford sought contributions from the European Space Agency, the Chinese National Space Agency, the Indian Space Research Organisation, and the United Arab Emirates Space Agency. This is thought to be the first time that all missions in orbit around Mars have collaborated on a single project. Each group examined data from their satellites orbiting Mars to look for a new crater, or any other tell-tale signature of an impact (e.g. a dust cloud appearing in the hours after the quake).
After several months of searching, the team announced today that no fresh crater was found. They conclude that the event was instead caused by the release of enormous tectonic forces within Mars’ interior. The results, published today in the journal Geophysical Research Letters, indicate that the planet is much more seismically active than previously thought.
Dr Fernando said: ‘We still think that Mars doesn’t have any active plate tectonics today, so this event was likely caused by the release of stress within Mars’…