No. 111/2020

WHAT DOES MARS TEACH US ABOUT EARTH, MR RUESCH? In the coming years, a European ExoMars Mission’s rover is scheduled to collect the first rock samples that will be sent fromMars to Earth. The geologist, Ottaviano Ruesch, will analyse the collected data. For decades, scientists have been studying Mars. “The main ques- tion is, of course, whether there is life there,” says Ruesch, “or, at least, an indication that there was at some time.” So far, no clear evidence has been discovered. But even if there never is any, the Red Planet still allows us some insights into the Earth’s past, because we don’t know exactly how life came about on our planet. Nearly all the evidence from that time has been wiped out. “Mars is effectively the Earth’s little brother. But one who hasn’t developed since childhood,” explains Ruesch. Whilst the Earth developed its own dynamics three and a half to four billion years ago, and its surface in the dense atmosphere was constantly altered by plate tectonics, volcanic activity and the weather kitchen, at some stage, Mars froze over time and the surface rock, in particular, barely changed at all. “For geologists, rocks are like books from the past,” says Ruesch. “In the Mars books we may be able to read about the condi- tions that prevailed when the first protozoa formed on Earth. We want to understand the context in which life evolves from organic material.” The ESA rover will explore the Oxia Planum plain. From its clay, researchers know that it is approximately 3.9 billion years old. “We will analyse everything in the finest detail, from the topography of the sur- face to the mineralogy and chemistry of the rock,” says Ruesch. Text JAN BERNDORFF The Swiss geologist, DR OTTAVIANO RUESCH , has conducted research for the European Space Agency, ESA, at Noordwijk in the Netherlands and for the American Space Agency, NASA, in Greenbelt. He is now a Sofja Kovalevskaja Award Winner, heading his own research project in the Institute for Planetology at the University of Münster. 7 HUMBOLDT KOSMOS 111/2020