“There is life out there Jim, but not as we know it”.

ExoMars scientists recently visited the Barberton greenstone belt to learn about early Earth.

How do you equip and instruct a robot to search for signs of life on Mars? You collaborate with scientists and geologists who are familiar with ancient geology and traces of early life on Earth. And that is exactly what researchers from the European Space Agency (ESA) and NASA are currently doing.

The Barberton greenstone belt is renowned for its well preserved Archaean rocks dating back 3,6 billion years and is one of the few places where scientists can study Earth’s formation years and early life forms on our planet. The evidence in the stone formations here shows that microbial life thrived under extreme conditions that would today be considered lethal, giving the scientist an idea of what to look for on the Red Planet.

The team of 20 scientists are involved in the preparation of the ESA-led ExoMars Mission that plans to send a robot to the Red Planet in 2018 and are blending their scientific know-how while visiting the Barberton/Badplaas area.

Dr Frances Westall, team leader for the Archaean field trip and Director of Research at CNRS in Orleans, puts it as follows: “The engineers and physicists build the analytical instruments for the rover that is dedicated to exobiology and geochemistry, but they should also know how geologists operate in the field in order to communicate the right information to it once it is on the surface of Mars.”   

Dr Jorge Vago, ExoMars project scientist ESA/ESTEC presented an overview of the mission to the group at Diggers Retreat. He said that more than 600 scientists are involved in the robotic exploration programme.

“If we want samples from Mars, we have to collaborate. This is the first mission ever to combine mobility with access to the subsurface. Having the next generation instruments is opening new fields for us.”

The rover will be equipped with, among others, drills to extract samples and we aim to search for signs of past or present life in the subsurface up to 2 meters deep. The rover will also search and test for biological markers such as amino acids, sugars and pigments to establish whether there is present life and look for images of fossils, their structures and organic residues of biological origin to see if their was life in the past.

“We will try to understand the geological environment in context and how it changes and collect samples which will be stored and brought back to earth on a future mission,” Jorge said.

It has been established that there was liquid water present and some of the processes considered important for the origin of life on Earth may have also been active during the youth of Mars. Due to the absence of moving crustal plates, scientists think there are areas with ancient rocks intact that can shed light on many questions relating to the objectives of this mission.

But why life on Mars?

“Conditions on Earth and Mars may have been similar in the very early stages. By establishing if there ever were life on Mars is fundamental for planning future missions that may include humans. One has to know what the conditions are like on the Red Planet,” Jorge concluded.

Dr Frances Westall, team leader for the Archaean field trip and Dr Jorge Vago, project scientist from the European Space Agency