space exploration

New findings on chimney-like rocks on Earth could hold the key to finding life on Mars

Researchers explain why their findings could prove crucial to NASA’s quest.

The search for life on Mars has taken a step forward with the NASA Curiosity rover’s discovery of organic matter on the bottom of what was once a lake. It may once have been part of an alien life form or it might have a non-biological origin – either way this carbon would have provided a food source for any organic living thing in the vicinity.

The discovery adds extra intrigue to NASA’s search for extra-terrestrial life forms themselves. When hunting remotely with one car-sized machine, the question is where best to focus your efforts. It makes sense to look for the same types of places we expect to find fossilised microorganisms on Earth. This is complicated by the fact that these fossils are measured in microns – mere millionths of a metre.

The Curiosity rover looks for certain sedimentary rocks deposited near water, as it did for the latest discovery. This is based on the latest geological advice about the best prospects. Yet which rocks to prioritise is still a matter of some debate – and it’s a question that is just as relevant to geologists trying to unlock the secrets of our own ancient world. The Earth’s rocks and fossils are the nearest thing we have to time machines.

For a century or so, geologists focused on a type of rock called a stromatolite – devoting long hours to crawling around in awkward spaces trying to find them. Stromatolites occur mainly in shallow water and are layered on a millimetre scale. Many of them are undoubtedly built by slimy microbial “biofilms”, but to cut a long story short we now appreciate there is more than one way to make a stripy rock – and they don’t all involve microbes.

Stromatolite city. Mike Beauregard/via Flickr [Licensed under CC BY 2.0]
Stromatolite city. Mike Beauregard/via Flickr [Licensed under CC BY 2.0]

More recently, geologists have become more interested in other types of rocks, including the “black smoker” tube-type deposits formed by hot hydrothermal water being squeezed out of the Earth’s crust in the deep sea. Slightly easier to examine are similar chimney-like formations found in certain alkaline lakes around the world.

Mono Lake

One place on Earth where these chimneys occur is Mono Lake in California, a vast and beautiful stretch of water several hundred miles north of Los Angeles on the eastern slope of the Sierra Nevada mountains. In October 2014, our team obtained permission from the California State Parks to examine and sample some of the calcium carbonate chimneys that have formed there.

The rocks, which are frequently between two and three metres tall, are very young in geological terms, usually only tens of thousands of years old. But since first being described by the famous American geologist Israel Russell in 1889 they have proven an excellent natural laboratory for groups of scientists trying to understand how these structures came about.

Exploration begins.Photo credit: Alexander Brasier
Exploration begins.Photo credit: Alexander Brasier

Before our visit, geologists were essentially divided about these chimneys. A group we might call “pure geochemists” proposed they were nothing to do with microbes, but produced by calcium-rich spring waters coming into contact with the alkaline lake, with its abundance of carbonate ions.

A smaller opposing camp agreed it should be possible for these structures to emerge in the way that pure geochemists were suggesting. But they pointed out that, in the few recorded observations of carbonate rocks forming at the lake in the 19th and 20th centuries, some kind of biofilm did appear to have an influence. They also cited other studies that had shown that waterborne microbes called cyanobacteria did produce slimy substances that can accumulate calcium.

We went to Mono Lake to find out who was right. Our six-strong expedition divided into two factions: one looked for chimneys on the lake bottom using a research boat, while the other explored the famous “tufa towers” that rise up from the lake shore.

Tufa towers on the shoreline. Photo credit: Alexander Brasier
Tufa towers on the shoreline. Photo credit: Alexander Brasier

The boat party toiled and cursed the astonishingly salty waters of the lake, while the shore party made steady progress with the invaluable assistance of local state park ranger, Dave Marquart. Their peace was interrupted only by a phone call from the stranded boaters requesting they urgently try to find someone with a four-wheel drive capable of pulling the boat back out of the water – luckily help was at hand.

One of the sites the shore party visited was in Marquart’s own back garden to the north-west of the lake. The rocks there were part of a set of ancient chimneys formed along a small tectonic fault. Their features suggested they had been built by microbes, but we needed to send them to a lab to be sure.

Microbial ‘threads’

Using an optical microscope, we were able to see dark thread-like structures entombed in slices of the rock. As we outline in our new study published in Geobiology, these “threads” are millions of fossilised photosynthesising cyanobacteria that once surrounded waters rising from a spring on the lake floor.

We sent the samples to Australia for further testing to establish whether the microbes played a key role in building the chimneys. This revealed surrounding patches of carbon and nitrogen, which we took to be fossilised cyanobacterial slime. This slime traps calcium and when it breaks down it creates calcium carbonate, entombing any living and dead cells in rock.

We found other ways in which this microbial slime had affected the fabric of the rock: grains of quartz and aluminosilicates that were clearly sand that had got stuck there, too.

Thread-like filaments in the Mono Lake rock.Photo credit: Alexander Brasier
Thread-like filaments in the Mono Lake rock.Photo credit: Alexander Brasier

In short, we found evidence that cyanobacteria formed tubular mats around rising spring water in the ancient Mono Lake – probably producing the majority of the resulting chimneys there, though there may be examples of “pure geochemistry” chimneys as well. This suggests that these rock formations do indeed represent a promising and fairly large target for exploring ancient or extra-terrestrial life.

They have the added advantage that the calcite rocks in question are geologically quite stable. This means the fossils could potentially be preserved for a very long time – easily hundreds of millions, quite plausibly billions of years.

To our knowledge no chimneys have been found on Mars yet, but they are not common on Earth and there is every chance that they have a Martian equivalent. There, and on other planets and moons, we should be looking for areas with conditions as similar as possible to where these chimneys exist on Earth – volcanic rocks where spring waters might once have risen through the bedrock into an alkaline lake. Without any question, NASA’s hunt for suitable rocks on the red planet should make finding them a high priority.

Alexander Brasier, Lecturer in Geology, University of Aberdeen; David Wacey, Australian Research Council Future Fellow, University of Western Australia and Mike Rogerson, Senior Lecturer in Earth System Science, University of Hull

This article first appeared on The Conversation.

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Swara Bhasker: Sharp objects has to be on the radar of every woman who is tired of being “nice”

The actress weighs in on what she loves about the show.

This article has been written by award-winning actor Swara Bhasker.

All women growing up in India, South Asia, or anywhere in the world frankly; will remember in some form or the other that gentle girlhood admonishing, “Nice girls don’t do that.” I kept recalling that gently reasoned reproach as I watched Sharp Objects (you can catch it on Hotstar Premium). Adapted from the author of Gone Girl, Gillian Flynn’s debut novel Sharp Objects has been directed by Jean-Marc Vallée, who has my heart since he gave us Big Little Lies. It stars the multiple-Oscar nominee Amy Adams, who delivers a searing performance as Camille Preaker; and Patricia Clarkson, who is magnetic as the dominating and dark Adora Crellin. As an actress myself, it felt great to watch a show driven by its female performers.

The series is woven around a troubled, alcohol-dependent, self-harming, female journalist Camille (single and in her thirties incidentally) who returns to the small town of her birth and childhood, Wind Gap, Missouri, to report on two similarly gruesome murders of teenage girls. While the series is a murder mystery, it equally delves into the psychology, not just of the principal characters, but also of the town, and thus a culture as a whole.

There is a lot that impresses in Sharp Objects — the manner in which the storytelling gently unwraps a plot that is dark, disturbing and shocking, the stellar and crafty control that Jean-Marc Vallée exercises on his narrative, the cinematography that is fluid and still manages to suggest that something sinister lurks within Wind Gap, the editing which keeps this narrative languid yet sharp and consistently evokes a haunting sensation.

Sharp Objects is also liberating (apart from its positive performance on Bechdel parameters) as content — for female actors and for audiences in giving us female centric and female driven shows that do not bear the burden of providing either role-models or even uplifting messages. 

Instead, it presents a world where women are dangerous and dysfunctional but very real — a world where women are neither pure victims, nor pure aggressors. A world where they occupy the grey areas, complex and contradictory as agents in a power play, in which they control some reigns too.

But to me personally, and perhaps to many young women viewers across the world, what makes Sharp Objects particularly impactful, perhaps almost poignant, is the manner in which it unravels the whole idea, the culture, the entire psychology of that childhood admonishment “Nice girls don’t do that.” Sharp Objects explores the sinister and dark possibilities of what the corollary of that thinking could be.

“Nice girls don’t do that.”

“Who does?”

“Bad girls.”

“So I’m a bad girl.”

“You shouldn’t be a bad girl.”

“Why not?”

“Bad girls get in trouble.”

“What trouble? What happens to bad girls?”

“Bad things.”

“What bad things?”

“Very bad things.”

“How bad?”

“Terrible!!!”

“Like what?”

“Like….”

A point the show makes early on is that both the victims of the introductory brutal murders were not your typically nice girly-girls. Camille, the traumatised protagonist carrying a burden from her past was herself not a nice girl. Amma, her deceptive half-sister manipulates the nice girl act to defy her controlling mother. But perhaps the most incisive critique on the whole ‘Be a nice girl’ culture, in fact the whole ‘nice’ culture — nice folks, nice manners, nice homes, nice towns — comes in the form of Adora’s character and the manner in which beneath the whole veneer of nice, a whole town is complicit in damning secrets and not-so-nice acts. At one point early on in the show, Adora tells her firstborn Camille, with whom she has a strained relationship (to put it mildly), “I just want things to be nice with us but maybe I don’t know how..” Interestingly it is this very notion of ‘nice’ that becomes the most oppressive and deceptive experience of young Camille, and later Amma’s growing years.

This ‘Culture of Nice’ is in fact the pervasive ‘Culture of Silence’ that women all over the world, particularly in India, are all too familiar with. 

It takes different forms, but always towards the same goal — to silence the not-so-nice details of what the experiences; sometimes intimate experiences of women might be. This Culture of Silence is propagated from the child’s earliest experience of being parented by society in general. Amongst the values that girls receive in our early years — apart from those of being obedient, dutiful, respectful, homely — we also receive the twin headed Chimera in the form of shame and guilt.

“Have some shame!”

“Oh for shame!”

“Shameless!”

“Shameful!”

“Ashamed.”

“Do not bring shame upon…”

Different phrases in different languages, but always with the same implication. Shameful things happen to girls who are not nice and that brings ‘shame’ on the family or everyone associated with the girl. And nice folks do not talk about these things. Nice folks go on as if nothing has happened.

It is this culture of silence that women across the world today, are calling out in many different ways. Whether it is the #MeToo movement or a show like Sharp Objects; or on a lighter and happier note, even a film like Veere Di Wedding punctures this culture of silence, quite simply by refusing to be silenced and saying the not-nice things, or depicting the so called ‘unspeakable’ things that could happen to girls. By talking about the unspeakable, you rob it of the power to shame you; you disallow the ‘Culture of Nice’ to erase your experience. You stand up for yourself and you build your own identity.

And this to me is the most liberating aspect of being an actor, and even just a girl at a time when shows like Sharp Objects and Big Little Lies (another great show on Hotstar Premium), and films like Veere Di Wedding and Anaarkali Of Aarah are being made.

The next time I hear someone say, “Nice girls don’t do that!”, I know what I’m going to say — I don’t give a shit about nice. I’m just a girl! And that’s okay!

Swara is a an award winning actor of the Hindi film industry. Her last few films, including Veere Di Wedding, Anaarkali of Aaraah and Nil Battey Sannata have earned her both critical and commercial success. Swara is an occasional writer of articles and opinion pieces. The occasions are frequent :).

Watch the trailer of Sharp Objects here:

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This article was published by the Scroll marketing team with Swara Bhasker on behalf of Hotstar Premium and not by the Scroll editorial team.