The scientist joins the next adventure on Mars

Kirsten Siebach has to persevere a little longer, waiting for her ship to arrive.

That ship is in space and is carrying a rover called Perseverance to Mars. And Siebach, a Martian geologist at Rice University, is now one of 13 scientists recently selected by NASA to help run the rover and explore the samples that will eventually be returned to Earth.

An illustration shows the Perseverance rover, now on its way to Mars, and its PIXL instrument in operation. Kirsten Siebach, a Martian geologist at Rice University, is one of 13 scientists selected to help run the rover. Image courtesy of NASA / JPL-Caltech

The rover, launched in July and landing next February, is the first of three missions that will bring back pieces of the Red Planet. Perseverance will identify, analyze, and then collect samples that scientists hope contain signs of ancient microbial life.

A second mission led by the European Space Agency will collect the promising samples collected and launch them into the orbit of Mars. A third mission will dock with the orbiter, collect the samples and take them to Earth, probably in the early 1930s.

Siebach, assistant professor of Earth, Environmental and Planetary Sciences, will be a main actor in the first mission, helping direct Perseverance as he pauses along a predetermined path to look for interesting features and select precious champions. His proposal was one of 119 submitted to NASA for funding.

Kirsten Siebach

“Everyone who has been selected to join the team should spend some time on general operations in addition to doing their own research,” he said. “My co-investigators here at Rice will do research to understand the origin of the rocks observed by Perseverance, and will also participate in the operation of the rover.”

That task, which was not unknown to her as a member of the Curiosity rover team, will help her select Mars rock and sand targets for analysis by Rice data scientist Yueyang Jiang, an expert in learning algorithms. automatic, and the researcher Gelu Costin, a mineralogist. .

“Since there is only one rover, the entire NASA team has to agree on what to watch, analyze, or where to drive on any given day,” Siebach said. “None of the rovers’ actions are a one-sided decision. But it is a privilege to be part of the discussion and get to support the observations of rocks that will be important to our understanding of Mars for decades. “

The landing site, the 28-mile wide Jezero crater, was selected for its history; it once housed a lake and a river delta where microbial life may have thrived over 3 billion years ago. Siebach is particularly enthusiastic about studying carbonates, the products of atmospheric carbon dioxide dissolved in water that on Earth usually settle in the landscape as limestone. They often contain fossils.

“There are huge packets of limestone all over the Earth, but for some reason it’s extremely rare on Mars,” he said. “This particular landing site includes one of the few carbonate orbital detections and appears to have a couple of different units, including carbonates, within this lake deposit. Carbonates will be the highlights we are looking for, but we are interested in virtually all types of minerals. “

A color image of Jezero Crater, the target of NASA’s Perseverance rover. Kirsten Siebach, a Martian geologist at Rice University, is one of 13 scientists selected to help run the rover. Image courtesy of NASA / JPL-Caltech / MSSS / JHU-APL

The primary tool Rice’s team will use on Perseverance is PIXL, short for Planetary Instrument for X-ray Lithochemistry, designed to identify chemical elements while providing close-ups of soil and rocks with a resolution the size of a grain of salt. . .

Siebach, Liang, and Costin plan to develop computational and machine learning methods that produce mineral maps of samples based on their high-resolution chemistry. They also aim to establish a context for the champions who will eventually return to Earth and could reveal the signatures of historical life on Mars.

It will take a couple of months after landing to validate Perseverance before Siebach and the others can begin their scientific investigation. Then the long game begins.

“From time to time, something hits Mars hard enough to knock out a meteorite, and it lands on Earth,” he said. “We have some. But we have never been able to select the provenance of a sample and understand its geological context. So these champions will be revolutionary “.