Will we find life on Mars? It’s about a 50/50 chance
‘If we find life that’s exactly like Earth, we could all be Martians. If it is different, it means there may be other places in our solar system with life’
Mankind has a “50/50” chance of finding evidence of life on Mars within the next three years, scientists working on the forthcoming rover mission predict.
The British-led team conducting trials for the Exomars robot said plans to excavate deep below the Martian surface for the first time dramatically improved the odds of discovering past or present extraterrestrial life.
Previous missions have mainly analysed surface rocks and topsoil. However, scientists believe the red planet’s thin atmosphere and corresponding intense radiation mean all but deeply hidden evidence of life will have been eradicated.
By contrast, a European Space Agency (ESA) craft, due to launch in 2020 and arrive the following year, will be fitted with a 2m (7ft) drill.
ESA’S first Mars rover, will also carry state-of-the-art lasers that can detect the presence of DNA by analysing the way molecules of dirt vibrate.
Led by Airbus, a forward testing “Exofit” team is trialling a prototype vehicle in the Tabernas desert of southern Spain.
Dr Susanne Schwenzer, the team’s astrobiologist, said: “The chances are just about 50/50. We have a very good chance – we are going to a very, very interesting spot.”
Dr Ben Dobke, the Exofit project director, said: “If you’re going to find microbial evidence of life, it’s probably underneath the surface.”
Once on Mars, the solar-powered rover will attempt to navigate the rocky surface, excavate soil and relay other observations for a minimum of 90 days. Engineers driving the project hope it will function far longer.
Operating with a 20-minute delay, as it is being directed by mission control in Harwell, Oxfordshire, ESA will attempt to position the rover towards the edge of regoliths, areas of unconsolidated soil on bedrock, to obtain the best samples. Mark Shilton, the Airbus engineer commanding the prototype rover – nicknamed Charlie – from the team’s desert remote control centre, said: “It’s not like driving a car. There’s quite a complex software chain involved and it’s extremely slow and methodical. The challenge is that often the most interesting locations for the geologists are the hardest for the rover. Every move is planned out rigorously.”
With a 3.5cm-per-second top speed, the rover has an array of cameras mounted on a mast above it, while hanging off the rear are two boxes containing ground-penetrating radar.
Among the most sophisticated of the instruments is the RAMAN laser spectrometer, a technology never before sent to Mars, that can determine the chemical bonds of molecules by the way they move under light.
The ultimate prize for Exomars would be evidence of DNA, which would amount to proof that life exists on the red planet, or once did.
But if the craft sends back evidence of other organic molecules, such as amino acids, the ESA scientists will have to try to determine whether they are indigenous to Mars or arrived on the planet via an asteroid.
“We would be, of course, thrilled if we found DNA – that’s the proof,” said Dr Schwenzer. “But that assumes that life on Mars is exactly like life is on Earth … If you’re looking for a needle in a haystack, you need to ask what that needle might look like and how it might have changed over time.
“If we find life that’s exactly like Earth, we could all be Martians, which is a huge thing in itself. If life is different from what we have on Earth, that means life can come about very often, which means there could be other places in our solar system – icy moons, Europa with an ocean underneath, for example – where we also could have life.
“It may not be intelligent, but once you have microbial life that’s the hard step. Evolution then runs its course.”
Blasting off from Earth around the same time in 2020 will be a rival Nasa mission, named Mars 2020.
Unlike Exomars, the US probe will have a potential operating period of years because it will be powered by a nuclear cell. It will also carry a drill to excavate soil to be transported back to Earth by a future ESA-NASA Mars “sample-return” mission.
The target location for Exomars, to be announced next month, will be a product of balancing the need to land in a geologically promising area with the correct altitude requirements. Because the Russian-built lander will operate by parachute, the team must ensure the atmosphere over the landing zone is thick enough to sufficiently slow the craft.
Surveying the mock landing site in Spain, which provided a setting for films such as The Good, The Bad and The Ugly and Indiana Jones and the Last Crusade, Mr Dobke was philosophical.
“If it lands and successfully deploys then that would be a massive achievement … because around 50per cent of all missions to Mars fail – they don’t even land,” he said. “But what drives this is that human question that transcends science and everything else – are we alone; is there something else out there?
“Even if it’s not intelligent, it opens up the possibility of looking out into the sky and thinking there’s other stuff out there, it’s not just an expanse of nothingness.”