News & Stories

Geology: Understanding the discovery of water on Mars

Geology provides a framework to interpret the discoveries being made on other planets, like that of water on Mars.

Astronomers took us to Mars. But it is often geologists that are helping to satisfy our hunger for knowledge of the red planet. Geologists sit at the interplay between physics and chemistry. They are skilled at bringing information together to help understand planet processes.

Geologists understand the interplay between fluids, minerals and soil. Geology provides a framework to interpret the discoveries being made on other planets, like that of water on Mars. 

Dr Garry Davidson is a geologist with particular expertise in hydro-geochemistry. Hydro-geochemistry examines water chemistry to determine where groundwater has been and what has happened to it along its journey. 

“Sample by sample and image by image geologists have been piecing together a history of Mars. Geologists have deduced that there was once an abundance of water on Mars. Through physical sampling, they’ve discovered that the polar ice on Mars is water ice,” said Dr Davidson.

"What we did not know, what this new evidence tells us, is that sometimes water on Mars still flows."  

What is the significance of flowing water on Mars?

The fixation with water on Mars is that, on Earth we have a water based life, and if we have running water on Mars it is possible that some sort of water based life exists on Mars today

This discovery also helps us to further understand the processes on Mars. 

“Having something dynamic like water appearing and disappearing on the surface, shows that Mars is not a dead planet. It is still an energetic but cryptic and subtle planet full of hidden processes.” 

Predictions are that water on Mars should boil, because pressures on Mars are very low. 

“If you take water to the top of Mt Everest, you don’t have to heat it very far before it boils. On Mars, it is the same effect, but on steroids. This is one of the reasons that water was thought not to exist on Mars,” said Dr Davidson.

“But, there are some circumstances where you can change the properties of that water and it can last longer. The saltier water is, the more likely it is to stay resident for a longer period. 

“This new bit of information confirms that salty water is present on Mars and that it is present today.”

What’s next?

Where are these salty waters coming from? What is their evolution? How do they fit in to the martian ecosystem? 

 “If they can investigate these systems into the shallow subsurface and they find life inside one of these flowing systems, everyone would be incredibly excited. But, it might be a long time before they can do that,” said Dr Davidson.

“It’s a great time to be getting into this area of the science. If people are excited by this and want to be a part of it, there’s never been a better time.” 

“We’re in an era now where there is more involvement from institutions around the world in the space program than there has ever been. This is partly because NASA and the European Space Agency, and other organisations, are putting vast amounts of information out there for other institutions to interpret.”

Students are now actively involved in interpreting the data, which they can access almost in real time. 

“A student could actually contribute to a mission.”

While planetary geology is not a high employment area, the skills would be very transferable into the mineral industry, oil and gas industry or environmental science. 

“A student could specialise in this field, indulge their curiosity and then apply those skills within industry down the track. It’s a win-win.” 

What could you study?

The University of Tasmania has a classical geological degree that provides an ideal foundation to follow a fascination for planetary science. 

“Many university’s have narrowed their focus to specialise in environmental geology or similar. The University of Tasmania’s geology degree is linked to a major research group, the Centre for Excellence in Ore Deposit Research (CODES), which is internationally renowned. For this reason we’ve maintained a degree that is very strong in the fundamentals,” said Dr Davidson.  

“Students can then follow a specialisation of their choice through dedicated research.”

Banner image credit: NASA