Curiosity gets to the bottom of Mars
Max Planck researchers use the rolling laboratory to search for water and organic compounds
It weighs 900 kilograms, has ten scientific instruments on board and is the most powerful laboratory ever sent to our neighbouring planet: the Curiosity rover. It will herald a new era of Mars research. The team working on Mars Science Laboratory, as the US space agency NASA’s mission is officially known, includes scientists from the Max Planck Institute for Solar System Research in Katlenburg-Lindau/Lower Saxony. In addition to searching for organic compounds in the Martian soil, they are particularly interested in the composition and nature of the rock.
Mars is the most-visited planet in our solar system: since the landing pioneers Viking 1 and 2 touched down in the red desert sand in 1975, four further space probes have radioed data back to Earth from the surface of the planet. Three functioning satellites are currently orbiting Mars.
Nevertheless, our neighbouring planet still harbours many mysteries: Does the soil contain carbonaceous organic substances? Are there even any indications of bacterial activity? Which processes formed the surface of Mars we see today? And what about water, which at some time flowed across the planet in huge river beds and is still hiding in the ground as ice in some places - what was its role in all this?
“The Gale crater, where Curiosity is to land, is a perfect starting point to investigate these questions,” says Walter Goetz from the Max Planck Institute for Solar System Research. Goetz is a member of the research team involved in the mission. The crater lies in the southern hemisphere very close to the equator and has a diameter of 154 kilometres. It formed more than three billion years ago in a meteorite impact.
The layered structure of the high mountain in the middle of the crater is particularly useful in enabling scientists to look into past eras of Martian evolution. Images from the orbit also show indications for erosion on the lower part of the mountain. “As far as we can judge, the form and mineralogy of the mountain indicate that liquid water has also formed the structures we see today,” says Goetz.
The Max Planck researcher will mainly use measurement data from the Mars Hand Lens Imager (MAHLI) camera. The instrument provides a resolution of 20 to 30 micrometres per pixel and allows the geologist to look closely at individual sand grains in the Martian soil. “The size, form, colour and mineralogical composition of the particles allow conclusions to be drawn about how the terrain evolved over the past billion years - whether the particles were formed in situ or whether wind transported them into the Gale crater, for example,” explains Walter Goetz. He will be accompanying the mission at the Jet Propulsion Laboratory (JPL) in Pasadena/California during the next three months.
Walter Goetz is also hoping for measurement data from the Chemistry and Mineralogy (CheMin) spectrometer, which uses X-rays to investigate the soil samples. “The research team in Pasadena will view the data from all the instruments on a daily basis in order to determine the rover’s route for the next day,” is how the researcher describes the tasks during the mission.
Fred Goesmann is also supporting the mission from the Max Planck Institute in Katlenburg-Lindau. The physicist is one of the scientists working on the Sample Analysis at Mars (SAM) instrument. “SAM is not an individual instrument, but rather a complex, automated laboratory,” says Goesmann. An ingenious sequence of sieves, ovens, spectrometers and other measuring instruments allows gas and soil samples to be analysed in detail.
The main task of the 38-kilogram complex is to search for organic compounds. “If life existed on Mars in the past, it must have left behind traces of this type,” says the scientist.
The Max Planck Institute for Solar System Research has been involved in five Mars missions organised by the American and European space agencies since 1996. Four years ago the Institute played an important role in NASA’s Phoenix landing mission. The camera on board, which succeeded in taking images of frozen water in the Martian soil for the first time, was developed and constructed by scientists and engineers in Katlenburg-Lindau. The Max Planck scientists are currently developing an instrument which is to investigate organic molecules on the Martian surface for ESA’s planned mission ExoMars.
BK / HOR