Where did the Martian Meteorites come from?

Researchers at Curtin University have pinpointed the likely origin of a group of Martian ejecta using machine learning algorithms and high-resolution planetary images. The new research published in Nature Communications shows the likely origin of these meteorites is the Tooting crater in the Tharsis region of Mars, which is the largest volcanic province in the solar system. 

“In this study, we compiled a new database of 90 million impact craters using a machine learning algorithm that allowed us to determine the potential launch positions of Martian meteorites,” Dr Lagain said.

“By observing the secondary crater fields – or the small craters formed by the ejecta that was thrown out of the larger crater formed recently on the planet, we found that the Tooting crater is the most likely source of these meteorites ejected from Mars 1.1 million years ago.

Over the last 20 million years there have been 166 Martian meteorites to land on Earth, however, their precise origins were unknown.

The lead researcher of this study, Dr Anthony Lagain from Curtin University’s Space Science and Technology Centre in the School of Earth and Planetary Sciences, said that the new findings would help provide the context to unravel the geological history of the Red Planet.

“For the first time, through this research, the geological context of a group of Martian meteorites is accessible, 10 years before NASA’s Mars Sample Return mission is set to send back samples collected by the Perseverance rover currently exploring the Jezero crater.”

Co-lead Professor Gretchen Benedix, also from Curtin University’s Space Science and Technology Centre, said the algorithm that made this possible was a major step forward in how scientists can use the terabytes of planetary data available.

“We would not have been able to recognise the youngest craters on Mars without counting the tens of millions of craters smaller than one kilometre across,” Professor Benedix said. 

This research also infers a thermal anomaly under Tharsis and provides evidence for a mantle temperature of between 1714°C and 1835°C which is hotter than previous estimates from in-situ rock analyses in Guvsev, Gale, and Meridiani craters.

“This finding implies that volcanic eruptions occurred in this region 300 million years ago, which is very recent at a geological time scale. It also provides new insights on the structure of the planet, beneath this volcanic province.”

The algorithm was developed in-house by an interdisciplinary group that included members from CSIRO, the Curtin Institute for Computation and the School of Civil and Mechanical Engineering with funding from the Australian Research Council.

Using the fastest supercomputer in the Southern Hemisphere, the Pawsey Supercomputing Centre, and the Curtin HIVE (Hub for Immersive Visualisation and eResearch), researchers analysed a very large volume of high-resolution planetary images through a machine-learning algorithm to detect impact craters.

The research also involved experts from Curtin’s Space Science and Technology Centre, Curtin’s Earth Dynamics Research Group, the Western Australian Museum, the CSIRO - Pawsey Supercomputing Centre, the University of Toulouse in France, and the University Félix Houphouët-Boigny in Africa.