Further evidence has emerged that Mars still has some liquid water

Scientists analysing images of Mars have found even more signs that, in rare circumstances, Mars may have water flowing across its surface.

Mars is supposed to be a dead, dry planet. There are clear signs that liquid water used to flow across its surface - remember Nasa mocking up that video of the Mars of 3.7 billion years ago? - but one of the Curiosity rover’s jobs right now is to investigate what we take to be ancient river bed.

This makes it very surprising indeed that scientists saw dark, water-like streaks in the red dust, in 2011. This should not be happening on a planet with no atmosphere.

To be clear, this isn’t proof that there’s liquid water on Mars - it’s just that we’ve seen something that looks a heck of a lot like liquid water. Here’s a slideshow of eight images showing what we’re talking about, provided by Nature:

Those black lines, as spotted by the Mars Reconnaissance Orbiter, are known as “recurring slope lineae”, and they darken the Martian soil just as water darkens soil on Earth. They were originally found two years ago at seven sites in the highlands of southern Mars, at middle latitudes which warm up in the summer and freeze again in the winter.

This latest study, by the same team of planetary scientists led by Alfred McEwen of the University of Arizona in Tucson, has found a further 12 sites with streaks, all on or near the equator. The equator has roughly the same temperatures year-round, and that means that - if there’s liquid water flowing on the surface - there must be a mechanism in place to replenish it. Mars’ low atmospheric pressure means that liquid water on the surface should sublimate into a gas almost immediately.

We now know that there’s quite a lot of water on Mars, be it frozen on the surface at the poles, under the surface elsewhere on the planet, or bound up with the soil itself. The implication of a flowing water source is that it might be the most likely location of life that still exists on Mars - but, conversely, that also makes it more crucial that we don’t send improperly sterilised probes there. If those Earth microbes are to survive anywhere on Mars - and scientists recently discovered a whole new species of microbe that could survive in even the most sterile of spaceship construction labs - then they’ll survive on these slopes.

It's also exciting for future colonists, who will save on energy if they don't have to heat up ice for drinking water. Our best chance of figuring out the exact nature of these lines on Mars is from afar, with the Mars Reconnaissance Orbiter, until we can decide what further action to take. Perhaps even the first colonisers, whoever they be (maybe it'll be Mars One, who want to send people there on a one-way mission starting from 2024) will be able to take advantage of that water source.

Dark streaks on Mars that may be water. (Image: NASA/JPL-Caltech/U. of Arizona)

Ian Steadman is a staff science and technology writer at the New Statesman. He is on Twitter as @iansteadman.

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The answer to the antibiotics crisis might be inside your nose

The medical weapons we have equipped ourselves with are losing their power. But scientists scent an answer. 

They say there’s a hero in everyone. It turns out that actually, it resides within only about ten percent of us. Staphylococcus lugdunensis may be the species of bacteria that we arguably don’t deserve, but it is the one that we need.

Recently, experts have cautioned that we may be on the cusp of a post-antibiotic era. In fact, less than a month ago, the US Centres for Disease Control and Prevention released a report on a woman who died from a "pan-resistant" disease – one that survived the use of all available antibiotics. Back in 1945, the discoverer of penicillin, Alexander Fleming, warned during his Nobel Prize acceptance speech against the misuse of antibiotics. More recently, Britain's Chief Medical Officer Professor Dame Sally Davies has referred to anti-microbial resistance as “the greatest future threat to our civilisation”.

However, hope has appeared in the form of "lugdunin", a compound secreted by a species of bacteria found in a rather unlikely location – the human nose.

Governments and health campaigners alike may be assisted by a discovery by researchers at the University of Tubingen in Germany. According to a study published in Nature, the researchers had been studying Staphylococcus aureus. This is the bacteria which is responsible for so-called "superbug": MRSA. A strain of MRSA bacteria is not particularly virulent, but crucially, it is not susceptible to common antibiotics. This means that MRSA spreads quickly from crowded locations where residents have weaker immune systems, such as hospitals, before becoming endemic in the wider local community. In the UK, MRSA is a factor in hundreds of deaths a year. 

The researchers in question were investigating why S. aureus is not present in the noses of some people. They discovered that another bacteria, S. lugdunensis, was especially effective at wiping out its opposition, even MRSA. The researchers named the compound created and released by the S. lugdunensis "lugdunin".

In the animal testing stage, the researchers observed that the presence of lugdunin was successful in radically reducing and sometimes purging the infection. The researchers subsequently collected nasal swabs from 187 hospital patients, and found S. aureus on roughly a third of the swabs, and S. lugdunensis on up to 10 per cent of them. In accordance with previous results, samples that contained both species saw an 80 per cent decrease of the S. aureus population, in comparison to those without lugdunin.

Most notably, the in vitro (laboratory) testing phase provided evidence that the new discovery is also useful in eliminating other kinds of superbugs, none of which seemed to develop resistance to the new compound. The authors of the study hypothesised that lugdunin had evolved  “for the purpose of bacterial elimination in the human organism, implying that it is optimised for efficacy and tolerance at its physiological site of action". How it works, though, is not fully understood. 

The discovery of lugdunin as a potential new treatment is a breakthrough on its own. But that is not the end of the story. It holds implications for “a new concept of finding antibiotics”, according to Andreas Peschel, one of the bacteriologists behind the discovery.

The development of antibiotics has drastically slowed in recent years. In the last 50 years, only two new classes of this category of medication have been released to the market. This is due to the fact almost all antibiotics in use are derived from soil bacteria. By contrast, the new findings record the first occurrence of a strain of bacteria that exists within human bodies. Some researchers now suggest that the more hostile the environment to bacterial growth, the more likely it may be for novel antibiotics to be found. This could open up a new list of potential areas in which antibiotic research may be carried out.

When it comes to beating MRSA, there is hope that lugdunin will be our next great weapon. Peschel and his fellow collaborators are in talks with various companies about developing a medical treatment that uses lugdunin.

Meanwhile, in September 2016, the United Nations committed itself to opposing the spread of antibiotic resistance. Of the many points to which the UN signatories have agreed, possibly the most significant is their commitment to “encourage innovative ways to develop new antibiotics”. 

The initiative has the scope to achieve a lot, or dissolve into box ticking exercise. The discovery of lugdunin may well be the spark that drives it forward. Nothing to sniff about that. 

Anjuli R. K. Shere is a 2016/17 Wellcome Scholar and science intern at the New Statesman