By Martin Van Kranendonk
The LifeSpringsMars mission concept arose through a confluence of connections and scientific ideas from different fields of study.
It started with Arizona State University’s Dr Steve Ruff, a member of the Spirit rover team, which discovered deposits of opaline silica (amorphous hydrated SiO2) in 2007 in the Columbia Hills of Gusev crater, Mars. The deposits were interpreted as products of ancient volcanic hydrothermal activity (Squyres et al., 2008). Following this discovery, Ruff and colleagues undertook detailed investigations of Spirit observations, comparing them with deposits from hot springs and fumaroles on Earth (Ruff et al., 2011, 2020; Ruff and Farmer, 2016). This led to the identification of remarkably similar deposits of opaline silica produced by hot springs at the edge of the Atacama Desert in Chile, where conditions are more similar to ancient mars than other locations on Earth. Most notable are the nodules of silica and their finger-like, or digitate structures in the hot spring outflow channels, features that are hallmarks of the silica deposits discovered with Spirit. The profound significance of this similarity is that the digitate structures of the Chilean hot springs contain, and are in part shaped by, the microbes that live in the outflow channels. This means that the digitate structures of opaline silica on Mars may represent a potential biosignature (Ruff and Farmer, 2016).
Left, the nodular hot spring opaline silica deposits with digitate structures at Columbia Hills discovered by the Spirit rover. Right, the nodular opaline silica deposits with digitate structures in a hot spring outflow channel at Tuja, Chile.
During this time, Prof Martin Van Kranendonk and his PhD student Tara Djokic were undertaking studies on the fossil-rich rocks of the 3.5 billion-year-old Dresser Formation of the Pilbara Craton in Western Australia, the site of the oldest convincing evidence of life on Earth. Tara’s project was to search for evidence of surficial hot springs in the ancient deposits, which had been predicted to occur on account of the presence of hundreds of large (km-deep x 10s m wide) hydrothermal silica-barite veins and associated mineral alteration of the basaltic rocks that host them. These are indicators of a large-scale fluid system that would have breached the surface to make hot springs. The problem was, neither Tara nor martin really knew what they were looking for, having not studied hot spring deposits in any great detail.
Aerial view of the boxwork set of hydrothermal silica-barite veins that underlie the c. 3.5 billion-year-old Dresser Formation in the Pilbara Craton of Western Australia.
In January 2015, Vmartin travelled to the Taupo Volcanic Zone in New Zealand to attend a Spaceward Bound meeting on the invitation of Prof Kathleen Campbell of the University of Auckland. She's one of the world’s leading experts on hot springs, who can study them almost literally in her own backyard. Kathy took Martin on a whirlwind tour of the amazing hot spring systems and their deposits, teaching him more in the field over 3 days than he could have learned from reading papers over 3 years. From this deep dive, he started to realise that the Dresser Formation may contain more evidence for hot spring deposits than he first thought.
Prof. Van Kranendonk coming to know the active hot springs of Rotorua in the Taupo Volcanic Zone, New Zealand.
Reciprocating the invitation, Martin invited Kathy to come to the field in Western Australia in June 2015, to see the Dresser Formation for herself. He guided her to classic localities where evidence of hot spring activity was suspected, and Tara showed off the new places that she had recently found. Kathy’s experience and impact was instant: “I know what that is, that, and that” pointing to three distinct types of deposits, ALL of which were associated with hot springs. A whole new world had opened up for us and Tara’s continuing work identified four sites with formerly active hot springs, including one that had a splashing geyser and another with terraced deposits (Djokic et al., 2017, 2021). Excitingly, there were hints that the hot springs deposits had been inhabited by communities of microbes (Djokic et al., 2017; Van Kranendonk et al., 2019) and contained concentrations of the elements required for an origin of life on land (Van Kranendonk et al., 2017, 2021)!
Prof. Kathleen Campbell admiring the Desert Sturt Peas and packed fragmental geology of the Pilbara Craton, Western Australia. Kathy was able to demonstrate that the rocks on the right were deposited at a point bar in the outflow channel of a hot spring.
Only a month later that same year, Prof David Deamer and his associate Dr Bruce Damer participated in the Australian Centre for Astrobiology’s Grand Tour across the northwestern part of Western Australia. This biennial trip starts with the living stromatolites of Shark Bay and travels back in time to the ancient rocks of the Pilbara, stopping along the way to observe life’s traces in rocks ranging n age from 1.86 billion years old to the 3.5 billion-year-old Dresser Formation.
Prof Deamer is a prebiotic chemist and a legend in origin of life studies, whereas “Dr Bruce” is a polymath and visionary systems ideas man. They were new acquaintances for our group. Towards the end of the trip, on the banks of the Shaw River, they outlined a developing hypothesis that was backed by the research that Prof Deamer had been working on for decades, of an origin of life in hot springs on land. They had come to the Pilbara to see the recently discovered evidence for hot springs in Earth’s oldest site with convincing evidence of life. Their model gave form and meaning to the discoveries in the Pilbara of microbially-inhabited, geochemically diverse, hot springs. The convergence of evidence for an origin of life on land from two very different fields was one of the most powerful experiences in the professional lives of all who were able to hear that discussion on the Shaw River. Outputs from that session have since been published (Van Kranendonk et al., 2017; Damer and Deamer, 2020).
Prof David Deamer (blue shirt, hands on chest) and Dr Bruce Damer (seated to his left) on the bank of the Shaw River in the Pilbara region of Western Australia tell the rest of the Grand Tour astrobiology fieldtrip participants their model for the origin of life in hot springs on land in 2017.
The other piece of the scientific puzzle fell into place in 2016 when Kathy was invited to act as the professional expert on a NASA “Ask an Astrobiologist program”. In the audience was Steve Ruff, who was eager to learn more about hot spring silica deposits (known as sinter) from one of Earth's experts. The Q&A portion of her virtual presentation was their first introduction to each other. The in-person version wold come during...you guessed it....another field trip.
This time, the trip included a different part of New Zealand, the Coromandel Peninsula, and a bespoke group including Steve, Kathy, Martin, Tara, and Kathy’s PhD student Ayrton Hamilton. Fieldtrips are wonderful things. There is no fancy accommodation, but there are long bumpy drives, scratches, fly bites, and sun, but the shared experience of discovery with like-minded people cannot be bettered. The days bouncing along tracks to look at tiny outcrops of fossilised hot springs and talking talking talking on the long drives and while eating dinner brings people together and clarifies scientific thought that, on its own in one single head, remains cloudy and unformed. Over that trip, we realised we were of one mind and that the features we had seen in rocks three and a half billion years old, in the active hot springs of the Taupo Volcanic Zone, in the fossilised remnants of the Coromandel Peninsula, and in the outcrops in the Columbia Hills on Mars could all have a common origin including, perhaps – just perhaps – the influence of microbial life.
Djokic, Campbell, and Hamilton watch from safely below while Ruff clambers up a cliff to see a fossilised hot spring silica sinter on the Coromandel Peninsula.
Steve Ruff, Bryan Drake, Diego Guido and Tara Djokic hitch a ride on the back of kathy Campbell's ute on the Coromandel Peninsula.
As a result of this trip and our recognition of the commonality of hot spring deposits over time and across planets, Steve invited Kathy and Martin to support him at a series of landing site workshops to decide where to send NASA's Mars2020 Perseverance Rover. Our team, which included Dr Bruce, Dr Jim Rice, and high school student Alex Longo, advocated for a return to the Columbia Hills to collect samples of the digitate opaline silica nodules to search for signs of past life. We presented at the 3rd landing site workshop in 2017 and 4th landing site workshop in 2018, where the Columbia Hills site was voted 3rd overall out of more than 30 original sites, with the highest scientific value. A reluctance by NASA and the Mars science community to revisit a previous site was the main drawback.
Steve Ruff addresses the assembly at the 3rd landing site workshop for the Mars2020 rover in Pasadena, California, in 2017.
Team Columbia Hills, plotting strategy at the 4th landing site workshop for the Mars2020 rover in 2018. From left to right: Tara Djokic, Erica Barlow, Alex Longo, Bonnie Teece, Kathleen Campbell, Martin Van Kranendonk, Steve Ruff.
Team Columbia Hills at the 4th landing site workshop for the Mars2020 rover in 2018. From left to right: Bruce Damer, Tara Djokic, Martin Van Kranendonk, Bonnie Teece, Kathleen Campbell, Steve Ruff, Jim Rice, Alex Longo, and Erica Barlow.
Martin Van Kranendonk presenting to the assembly at the 4th landing site workshop for the Mars2020 rover in 2018.
At the landing site workshops, we met Dr Mitch Schulte, NASA’s Program Scientist for Mars2020. Mitch came on the Astrobiology Grand Tour in 2018 and liked it so much that he came back to the Pilbara in 2019 and brought with him the science teams for both NASA's Mars2020 rover and the European Space Agency’s Rosalind Franklin ExoMars rover for a week-long field workshop on how to explore for signs of ancient life. See an interview about this trip below.
In June 2023, Mitch is coming back to the Pilbara, this time bringing along with him the Mars Exploration Program Science team, ESA’s ExoMars Project Scientist, and two members of the Australian Space Agency. We’ll talk a lot about LifeSpringsMars!
Another important connection to the team was made in 2017, again through an unconnected contact that Martin had with an old colleague from grad school back at the University of Toronto in the 1980s. Martin contacted Professor Eizo Nakamura at Okayama University in Japan about the possibility of him undertaking analysis of boron-rich laminated crusts that Martin and Tara had found associated with hot spring deposits in the Dresser Formation. Eizo is one of the world’s leading experts on boron and runs one of the cleanest geochemical labs in the world, hand built in an old medical building in the small town of Misasa, Japan. In fact, his lab – the Pheasant Memorial Laboratory at the Institute for Planetary Materials – was chosen to analyse some of the sample material returned from the Hyabusa II mission and is fully automated to enable analysis of samples returned from Mars.
As a result of the boron investigations, Eizo invited Martin to be cross-appointed at the Institute in 2018, the two re-connecting after more than 40 years.
The entrance to the Pheasant Memorial Laboratory at the Institute for Planetary Materials of Okayama University in Misasa, Japan.
And then, another field trip cemented Eizo within the rest of the group.
In 2019, as part of a research project headed by Martin and funded by the Australian Research Council, Eizo was invited along on a trip to sample the mixing zones between individual hot springs in Rotorua, New Zealand, together with Kathy’s group, Michael Rowe from the University of Auckland, and Jeff Havig and Trinity Hamilton from the University of Minnesota. On this trip, Eizo had one of those Ah-Ha! Moments so stereotyped of scientists, but nonetheless true. Over two days we had shown him a variety of fabrics in hot springs deposits that were formed by microbial activity, but when we bent down beside a green microbial mat that was being fossilised in situ by silica precipitated out of the underlying hot spring waters, Eizo completely understood the importance of hot springs in preserving signs of life in ancient deposits here, and on Mars.
The fieldtrip team at Champagne Pool, Rotorua in 2019. Eizo Nakamura is on the far right.
The wonderfully-named Orakei Korako hot spring in the Taupo Volcanic Zone, New Zealand. All of the white material is silica sinter, all the orange is microbial mat on the silica sinter. Note the many steaming vents.
Eizo Nakamura at his Ah-Ha! Moment at the Devils’ Cauldron of Orakei Korako. The orange-green mat here covers flowing hot spring waters and is being partially silicified in situ (white patches).
And it was at this moment that the LifeSpringsMars sample return mission concept to Columbia Hills was hatched. After NASA made the decision to send the Perseverance Rover to Jezero crater, Steve, Kathy, and Martin started to discuss the possibility of developing our own mission to Mars and when Eizo had his hot spring epiphany, the die was cast to start thinking about how we could make such a bold initiative happen.
Turns out that Eizo is good friends with the former Deputy Director General of JAXA/ISAS, Japan’s Space Agency, Dr Yoshifumi Inatani, and had a chat with him about the importance of the opaline silica deposits at Columbia Hills as an astrobiological target for sample return. Dr Inatani then tasked four junior JAXA/ISAS engineers to design a mission architecture for sample return to the Columbia Hills, and so LifeSpringsMars was born.
The first team meeting for the LifeSpringsMars mission team was held in 2019 in Misasa, Japan, funded by BHP and Okayama University. A second team meeting was held in Auckland, New Zealand in 2022 (after Covid), funded by the Royal Society of New Zealand, and a third team meeting will be held at UNSW in Sydney, Australia in early September 2023.
Close-up view of partially silicified microbial mat at the Devils’ Cauldron, Orakei Korako.
The first meeting of the LifeSpringsMars team in Misasa, Japan in 2019.
The JAXA/ISAS engineering team, including from left to right: Takao Maeda, Akihiro Iwasaki, Jun Asakawa, Naoya Ozaki, and Yosifumi Inatani.