Is there life on Mars? What New Zealand’s famous hot springs can tell us

New Zealand’s world-famous hot springs could help answer one of science’s biggest questions: Did life ever exist on Mars?

There is fascinating evidence — from ancient river valleys to key chemicals unearthed in Martian rocks — that the planet was once more habitable than it is today.

While much research has focused on the search for organic life, such materials would degrade over billions of years, harking back to a time when Mars was wetter and warmer than it is today.

That’s prompted scientists to look to Earth’s hot spring environments — believed to be geologically similar to the Martian silica discovered by NASA’s Spirit rover — to explore how certain telltale traces could have been preserved.

Professor Cathy Campbell, an astrobiologist at the University of Auckland, said Earth and Mars had similar early histories, including volcanic activity and flowing surface water.

This, she said, makes our hot springs “an ideal location” to search for materials bearing signatures of microbial life so that they can eventually be compared with samples brought back to Earth from Mars.

In a newly published study, scientists used sediments from the Rotokawa, Tikopia and Atiamuri geothermal systems in the central North Island, as well as other sediments collected from Chile.

At the Australian Synchrotron in Melbourne, researchers used cutting-edge technology to map the chemistry of microorganisms within materials on an unprecedented scale.

Lead author of the study, University of Auckland geochemist Associate Professor Michael Lowe, said the analysis also allowed the team to learn more about the environments in which the fossils were stored over millions to billions of years.

Their results suggest that at least some microorganisms in hot springs are able to gather different elements around themselves.

“This could serve as a chemical ‘fingerprint’ of life after other obvious evidence, such as organic carbon signatures, have been erased over time,” Lowe said.

One element in particular — gallium, a common ingredient in electronics — proved to be the most reliable chemical indicator of microorganisms.

“The next phase of our research is to understand why,” Lowe said.

“We hope that when we are able to bring Martian samples back to Earth, this method will provide a new and powerful tool for identifying whether life ever existed on Mars.”

The study was published in the journal Science Chemical Geologymarking the latest fascinating connection between New Zealand researchers and the Red Planet.

In addition to Campbell’s work over the years, New Zealand scientists have also participated in Testing a prototype micro-rovers in our volcanic valley; simulate the Martian atmosphere to look for clues to life; and even conduct experiments to see if concrete can be made from Martian soil.

Lowe said fundamental questions about past or present microbial life on the planet remain for scientists around the world, and NASA hopes to send a manned spacecraft to Mars by the 2030s.

“While this research explores new ways to search for life, there are still many unknowns and assumptions involved in this work,” he said.

“Only through careful investigations like this can we paint a picture of what early life on Mars, Earth or elsewhere might have been like, and the mechanisms by which it might have flourished.”

Billions of years later, the evidence is still waiting to be picked up by a future mission and returned to Earth.

Jamie Morton is a science and environment reporter. He joins The Herald Founded in 2011, he writes about conservation, climate change, natural disasters, and new technologies.