NASA has reported that its Curiosity rover has made another significant discovery on Mars.
Curiosity has drilled into a rock that contains clay minerals – an indication of formation in, or substantial alteration by, neutral water.
Scientists say the find is one more step towards showing conditions on Mars in the distant past could have supported life.
Many rocks studied previously were probably deposited in acidic water.
While this would not have precluded the possibility of micro-organisms taking hold on Mars, it would have been more challenging, scientists believe.
Identifying clays shows there were at least some locations on the planet billions of years ago where environments would have been much more favorable.
“We have found a habitable environment that is so benign and supportive of life that probably if this water was around and you had been there, you would have been able to drink it,” said John Grotzinger, Curiosity’s project scientist.
Curiosity rover drilled a powdered sample from a mudstone at its exploration site in Gale Crater, a deep impact bowl on Mars’ equator.
This was delivered to the two big onboard laboratories, Sam and Chemin, for analysis.
The rock sample was found to contain 20-30% smectite – a particular group of clay minerals.
Their high abundance and the relative lack of salt are strongly suggestive of a fresh-water environment for the mudstone’s formation.
The presence of calcium sulphates, rather than the magnesium or iron sulphates seen in previous rock analyses at other locations on the planet, adds to the evidence that the sampled rock in Gale was deposited in a neutral to mildly alkaline pH environment.
Mars Curiosity rover has drilled into a rock that contains clay minerals, an indication of formation in, or substantial alteration by, neutral water
Scientists think Curiosity probably drilled into an ancient lakebed.
The analysis also identified sulphur, nitrogen, hydrogen, oxygen, phosphorus and carbon – some of the key chemical elements for life.
Additionally, it found compounds in a range of oxidized states, meaning there were electrons moving through the environment. Those could have been co-opted as an energy source by simple life-forms, if they ever existed in Gale.
“What we’ve learned in the last 20 years of modern microbiology is that very primitive organisms – they can derive energy just by feeding on rocks,” explained Prof. John Grotzinger.
“Just like on [a] battery – you hook up the wires and it goes to a lightbulb and the lightbulb turns on. That’s kind of what a micro-organism would have done in this environment, if life had ever evolved on Mars and it was present here.”
Curiosity rover is assembling quite a catalogue of water evidence in the crater.
Already, it has seen the remains of an ancient riverbed system, where water once flowed perhaps a metre deep and quite vigorously.
The picture that seems to be emerging is one where sediments were transported downhill from the eroding crater rim into a network of streams that then flowed into the lake environment represented by the mudstone.
Curiosity is currently working in a small depression known as Yellowknife Bay, about half a kilometre from the location where it touched down last August.
NASA’s original mission plan was to head towards the big mountain that dominates the centre of Gale Crater, but the fascinating science at Yellowknife Bay has delayed this journey somewhat.
In recent days, operations have been slowed by a software glitch, requiring the vehicle to be run off its reserve computer.
There is also the imminent issue of solar conjunction, which will see Mars move behind the Sun as viewed from Earth, blocking communications.
All this means that Curiosity will be at Yellowknife Bay for a while yet.
“Basically, we can’t talk to the rover and the rover [can’t] talk to us for most of the month of April,” said Michael Meyer, the lead scientist on NASA’s Mars exploration programme.
“We’ll do some more science activities though the end of this month, [provided] the engineers confirm it’s safe for us to do those operations. But we will not do a second drill hole until after solar conjunction.”
When the rover does finally get to the mountain, known as Mount Sharp, the expectation, based on satellite imagery, is that it will again find clay minerals.
This will enable the robot to compare and contrast past environments.
The US space agency’s Opportunity rover, which continues to work nine years on from its landing, is also believed to be sitting on top of clay-bearing rocks at its exploration site far to the west of Gale. Opportunity, however, does not have Curiosity’s capability to assess those rocks.
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It seems the hottest new healthy food fad is “eating alkaline”as the actresses Gwyneth Paltrow and Kirsten Dunst have recently revealed they “eat alkaline”.
Jennifer Aniston drinks an alkaline smoothie every day and supermodel Miranda Kerr recently revealed that instead of drinking normal pH neutral water, she drinks only water alkalized by a special filter.
Our bodies are naturally alkaline, but its functions produce acid. This stresses out your digestive system, causing you to gain weight and feel lethargic. In short, health fanatics claim “going alkaline” is the fastest route to having more energy, a flat stomach and glowing skin.
“I’ve been a fan of eating alkaline for years,” says nutritionist Vicki Edgson.
“It’s basically about getting the balance right between alkaline and acidic foods. We can eat both types, but we need to ensure we eat more alkaline foods than acidic ones.”
“Acidic foods are, as the name suggests, acid-forming in the body,” explains Vicki Edgson.
“They can cause weight gain, a bloated stomach, tiredness and other health problems. Whereas alkaline foods help you stay in shape and feel and look younger.
“The other good thing about this way of eating is that it’s entirely un-faddy: it doesn’t cut out food groups or involve counting calories.”
So, could you be acidic? Signs include weight gain, poor digestion, bloating, tiredness and skin problems (dryness or spots). If so, it may be time to give alkaline eating a go.
The alkaline diet first came to prominence in America when Robert Young wrote the New York Times bestselling The pH Miracle. In it, he explains how he discovered that the pH of foods (i.e. whether they’re alkaline or acidic) affects our weight and health.
“Eating alkaline foods acts as a buffer for the stresses and strains of life, which are acid-forming,” says Robert Young.
He goes on to explain how the more alkaline you are, the healthier you’ll feel. You’ll be able to lose excess weight more quickly, you won’t feel bloated or tired and your skin will look better. In other words, your body will function more efficiently, he claims.
A typical diet of coffee, processed food, too much meat, alcohol, sugar, salt and stress can quickly cause us to become acidic – and poor health, weight gain and tiredness will follow.
Honestly Healthy. Eat With Your Body In Mind, The Alkaline Way, by Natasha Corrett and Vicki Edgson
So stress causes us to become acidic too?
“Yes”, says Vicki Edgson who has recently co-written a book on alkaline eating.
“Our long-hours culture is causing many of us to become acidic. Tiredness and stress are very acid-forming. However, what is even more so is anger and bitterness.
“It’s one thing to get a little stressed about daily chores, but if you hold on to feelings of anger and resentment for many months or years, you run the risk of becoming incredibly acidic, which can be detrimental to your health.”
The good news is, Vicki Edgson says, if you manage your stress and include plenty of alkalizing foods in your diet, you can tip yourself back into an alkaline state.
Organic chef, Natasha Corrett, who with Vicki Edgson co-wrote Honestly Healthy: Eat With Your Body In Mind, The Alkaline Way, discovered the benefits of this diet first-hand.
“My weight yo-yo’d for years and I tried lots of different diets,” she explains.
“Then, in 2009, I hurt my back. So my mum sent me to an ayurvedic acupuncturist who took one look at me and said: <<You’re completely acidic>>. He then asked me if I struggled to lose weight, felt bloated, stressed, heavy, tired and struggled to wake up in the mornings and concentrate during the day. He basically described how I felt most of the time.
“He put me on a three-week alkaline diet and within days I felt amazing. I’d never really heard of alkaline eating before but it seemed incredibly simple and I never felt hungry so it didn’t feel like a diet. My energy levels improved, my skin glowed, the weight fell off – and, crucially, it’s stayed off – and my sugar cravings vanished.”
Natasha Corrett continued on the alkaline diet after the 21 days were up and lost 28 lbs in a few months, taking her from a size 12 to a size 8.
“I love food and I hate to deprive myself, so I created alkaline recipes of my favorite foods. I love really succulent chocolate brownies so I made them without sugar, salt, wheat or gluten.”
All the alkaline recipes are in her new book. Vicki Edgson says that acidic foods aren’t necessarily a bad thing – if you look at the list of foods, you’ll see plenty of acidic ones that can be part of a healthy diet. It’s the ratio you need to get right.
She recommends 70% of what you eat should be alkaline and 30% acidic to help tip your body into an alkaline state. She also advises having plenty of fibre from fruit and vegetables, plus wholegrains, to help sweep out your digestive tract and reduce your acidity, as well as lots of water and sleep.
The way you cook your vegetables also has an impact. For example, raw spinach is alkaline, but when you cook it, it becomes acidic. For this reason you should try to eat your vegetables raw or just lightly steam them.
