This is what it looks like to fly past the Earth in a spaceship

Nasa's Juno probe flew past us in October, capturing footage of the Earth and Moon moving through space.

There are many images of our home planet taken from space, and they rarely fail to put things in perspective. Yet, have you ever seen our planet, from space, in motion?

The video above was taken by Nasa's Juno probe as it flew past us on 23 October. That grey mass to the left of the screen at the start, drifting right, is the Moon, orbiting the blue Earth. This is what it would look like to approach the Earth in a spaceship. It is incredibly cool. (And that music? That's a composition by Vangelis, the guy who did the soundtracks for Blade Runner and Chariots of Fire - Nasa has good taste.)

Juno, as its name may suggest, is on its way to explore Jupiter. It launched in August 2011, with enough momentum to reach as far as the asteroid belt before gravity pulled it back in towards the Sun - all part of Nasa's plan. As it reached the Earth again and skimmed past it received a gravity boost of a further 7.3km/s relative to the Sun, which should give it the velocity needed to reach Jupiter on the other side of the Solar System by July 2016. Once it's in orbit there, it will study the gas giant's clouds, and what's beneath them.

The video Nasa made of Juno's flypast opens with the probe roughly a million kilometres from Earth. The Moon's orbit is roughly 385,000km, which explains why the Moon shoots off to the right as Juno moves inside its orbit. Juno actually spins as it's flying along, twice per minute, so this video is a sped up one with two frames captured per minute of the same angle by Nasa engineers.

In other "things flying closely past the Earth" news, asteroid 2013 XY flew through our neighbourhood this morning:

It's probably between 30 and 70 metres across, which is considerably larger than the 15-20 metre Chelyabinsk meteor of February this year. And, best of all, we only spotted it five days ago. That's not a lot of warning for something potentially destructive (though, just to emphasise, there's no chance of this thing hitting us). Still, it goes to show just how big space is, and how little of it we know about, even in what we might consider our local community.

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

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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.