What more could be out there? Photo: Getty
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Nasa chief scientist says we're (possibly) only a decade away from finding alien life

It's increasingly clear that the Solar System is more life-friendly than we'd previously suspected.

Some provocative news today, as reported by Space.com - Nasa chief scientist Ellen Stofan told a panel yesterday that we're only "decades" from having "definitive proof" of alien life:

I think we're going to have strong indications of life beyond Earth within a decade, and I think we're going to have definitive evidence within 20 to 30 years," Nasa chief scientist Ellen Stofan said Tuesday (7 April) during a panel discussion that focused on the space agency's efforts to search for habitable worlds and alien life.

"We know where to look. We know how to look," Stofan added during the event, which was webcast live. "In most cases we have the technology, and we're on a path to implementing it. And so I think we're definitely on the road."

Former astronaut John Grunsfeld, also speaking on the panel agreed, arguing that evidence for life both in our Solar System and further afield is only "one generation away".

It's heady stuff, bolstered by a range of recent discoveries that have shown us that water is everywhere in the Solar System. Most prominently, we've got Europa, Enceladus and Ganymede, all large moons with vast oceans beneath their icy crusts; but we also know that smaller objects - which, to an extent, had been dismissed as dull and rocky until recently - are also wet, or at least in possession of some surface ice. That group includes Mercury and Ceres, and, of course, Mars. Together with our increasing awareness of the wateryness of asteroids and comets, and it does appear that the Solar System is a place of water - and water is the crucial factor for life as we know it, especially when liquid, as it appears is the case on some of Jupiter's and Saturn's moons where gravity and radiation make up for the distance from the Sun.

What life is present there is, if it exists, microbial at best. The chances that there's anything larger than bacteria floating around beneath the surface of Europa is so slim as to be effectively impossible, but that hasn't put a brake on the excitement felt around the space community right now. And this comes at an important time for Nasa, which is coming towards the end of its current generation of missions and preparing to pitch for funding for its next - and it will have to pick its targets carefully, as the appetite for space exploration within the US government is increasingly hostile to anything without a clear economic or prestige benefit, such as the next-gen Space Launch System heavy lift rocket. That makes the pure science of probes like, say, Cassini, harder to justify.

Despite receiving a slight budget increase in late 2014 after several years of cuts, at the end of March it was revealed that the Opportunity rover on Mars and the Lunar Reconnaissance Orbiter could both be victims of budget cuts imposed by Republicans in Congress, while key prestige projects - like the agency's much-feted plan to capture an asteroid and bring it into orbit around the Moon - have been repeatedly scaled- and pushed-back as technological and monetary challenges have grown in number. And there are those who question whether its disproportionate focus on Mars - and on the endless search for life elsewhere in the Solar System - is the most effective use of its resources.

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

Davide Restivo at Wikimedia Commons
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Scientists have finally said it: alcohol causes cancer

Enough of "linked" and "attributable": a new paper concludes that alcohol directly causes seven types of cancer.

I don't blame you if you switch off completely at the words "causes cancer". If you pay attention to certain publications, everything from sunbeds, to fish, to not getting enough sun, can all cause cancer. But this time, it's worth listening.

The journal Addiction has published a paper that makes a simple, yet startling, claim: 

"Evidence can support the judgement that alcohol causes cancer of the oropharynx [part of the throat], larynx, oesophagus, liver, colon, rectum and [female] breast"

So what's especially significant about this? 

First, scientists, unlike journalists, are very wary of the word "causes". It's hard to ever prove that one action directly led to another, rather than that both happened to occur within the same scenario. And yet Jennie Connor, author of the paper and professor in the Preventive and Social Medicine department at the University of Otago, New Zealand, has taken the leap.

Second, alcohol not only causes cancer of one kind – the evidence supports the claim that it causes cancer at seven different sites in our bodies. There was weaker evidence that it may also cause skin, prostate and pancreatic cancer, while the link between mouth cancers and alcohol consumption was the strongest. 

What did we know about alcohol and cancer before?

Many, many studies have "linked" cancer to alcohol, or argued that some cases may be "attributable" to alcohol consumption. 

This paper loooks back over a decade's worth of research into alcohol and cancer, and Connor concludes that all this evidence, taken together, proves that alcohol "increases the incidence of [cancer] in the population".

However, as Connor notes in her paper, "alcohol’s causal role is perceived to be more complex than tobacco's", partly because we still don't know exactly how alcohol causes cancer at these sites. Yet she argues that the evidence alone is enough to prove the cause, even if we don't know exactly how the "biologial mechanisms" work. 

Does this mean that drinking = cancer, then?

No. A causal link doesn't mean one thing always leads to the other. Also, cancer in these seven sites was shown to have what's called a "dose-response" relationship, which means the more you drink, the more you increase your chances of cancer.

On the bright side, scientists have also found that if you stop drinking altogether, you can reduce your chances back down again.

Are moderate drinkers off the hook?

Nope. Rather devastatingly, Connor notes that moderate drinkers bear a "considerable" portion of the cancer risk, and that targeting only heavy drinkers with alcohol risk reduction campaigns would have "limited" impact. 

What does this mean for public health? 

This is the tricky bit. In the paper, Connor points out that, given what we know about lung cancer and tobacco, the general advice is simply not to smoke. Now, a strong link proven over years of research may suggest the same about drinking, an activity society views as a bit risky but generally harmless.

Yet in 2012, it's estimated that alcohol-attributable cancers killed half a million people, which made up 5.8 per cent of cancer deaths worldwide. As we better understand the links between the two, it's possible that this proportion may turn out to be a lot higher. 

As she was doing the research, Connor commented:

"We've grown up with thinking cancer is very mysterious, we don't know what causes it and it's frightening, so to think that something as ordinary as drinking is associated with cancer I think is quite difficult."

What do we do now?

Drink less. The one semi-silver lining in the study is that the quantity of alcohol you consume has a real bearing on your risk of developing these cancers. 

On a wider scale, it looks like we need to recalibrate society's perspective on drinking. Drug campaigners have long pointed out that alcohol, while legal, is one of the most toxic and harmful drugs available  an argument that this study will bolster.

In January, England's chief medical officer Sally Davies introduced some of the strictest guidelines on alcohol consumption in the world, and later shocked a parliamentary hearing by saying that drinking could cause breast cancer.

"I would like people to take their choice knowing the issues," she told the hearing, "And do as I do when I reach for my glass of wine and think... do I want to raise my risk of breast cancer?"

Now, it's beginning to look like she was ahead of the curve. 

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.