What if the Mars Rover does find Proof of life?
Nasa engineers are pleased with the performance of the Curiosity Rover, but will it find evidence that Mars had the ability to harbour current or past life on Mars, writes BECCA WILSON
I SPY with my little eye – but what does Curiosity see? Last week Nasa’s Curiosity rover – the largest and most high-tech space exploration robot ever made – opened up its “eyes, ears and nose” to examine the surface of Mars.
The rover is part of Nasa’s Mars Science Laboratory (MSL) mission, with the prime goal of answering the question of whether ancient Mars had the capability to host microbial life.
Final and absolute confirmation that life either exists or used to exist on Mars raises profound questions about life and its potential to exist here and elsewhere. So the Curiosity is going to be answering some very big philosophical and biological questions.
As life was just emerging on our own planet 3.5 billion years ago, Mars also contained liquid water on its surface.
“In many respects Mars is a very Earth-like world, or at least it was billions of years ago. When life was first getting started on Earth we see extensive evidence for liquid water across the face of Mars,” says Dr Lewis Dartnell, research fellow in astrobiology at University College London.
“Studies of some of the hardiest life forms on Earth tell us that Mars may have been able to support life back then, and possibly even still today, underground,” he says.
Curiosity will add greatly to the knowledge we already possess in attempting to answer questions about Martian life. “We have tantalising evidence from previous spacecraft and Martian meteorites for a warmer, wetter past on Mars when life might have existed,” says Dr John Bridges, reader in planetary science at the University of Leicester.
Bridges is a member of the MSL science team and is leading a group of scientists from the UK and France that will study images and data collected by the rover.
“MSL may provide the ‘ground truth’ necessary to accurately determine how long water existed on the surface of Mars, what the composition of brines were, and thus whether Mars was habitable.”
Bridges has a particular interest in the Alpha Proton X-ray Spectrometer and ChemCam instruments that are built into the Curiosity. This equipment determines the quantity and variety of major elements in Martian rocks and soil, giving clues to the ancient Martian environment.
“A laser on Curiosity’s mast creates small pulses of plasma on rock surfaces which are analysed by the ChemCam spectrometers to determine compositions of elements including hydrogen,” explains Bridges.
“From this we can determine what the water temperatures, acidity and composition were and thus whether it was habitable.”
Nasa has released some analyses from ChemCam, after Curiosity zapped a rock with its laser for the first time. Initial data from the multi-wavelength camera confirms that the “Coronation” rock is basalt, a volcanic rock that is common on Mars.
A compilation of 30 laser-shot analyses also detected the presence of carbon from the carbon dioxide-rich atmosphere. Hydrogen was also found in the first but not subsequent shots. This suggests that the element, a constituent of water, is only present on the outer surface of the rock.
Bridges is unable to divulge many details about the analysis of data recently received from Curiosity, but confirms, “We are now getting a stream of exciting data and images. Hopefully the MSL mission will last several years or more and there is much more to come.”
MSL builds on the decades of preceding Mars missions and advances in technology. “MSL is a mission of our time, we couldn’t have done it five years ago,” says Kevin Nolan, lecturer in physics at the Institute of Technology Tallaght and author of the book, Mars, A Cosmic Stepping Stone. “Things that stand out with MSL are the combination of its sophistication and its size.”