Wakey wakey. Image: ESA
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After seven months in hibernation on a comet, the space probe Philae has woken up

ESA's space probe Philae has awoken on comet 67P/Churyumov–Gerasimenko after seven months in hibernation. 

On November 12, 2014, Rosetta ejected the dishwasher-sized, tendril-like limbed Philae into the quiet abyss of space. Its mission: to land on a comet with feeble gravity that moves 40 times the speed of a bullet:

Rosetta’s OSIRIS narrow-angle camera shows the Philae lander at 10:23 GMT (onboard spacecraft time) on 12 November, almost two hours after separation. Image: ESA

In a bid to become the new hero of new-age space technology, Philae, despite its harpoons malfunctioning, and despite its bumpy landings, found itself miraculously wedged in a rocky crevice on comet 67P Churyumov-Gerasimenko. Its rather fortunate position sent back (via Rosetta) some intriguing images of the comet’s shadowed surface:

A spot on the comet's surface before it landed is empty (left) and then after the landing a new blip appeared (middle and right). Image: ESA

A cosmic power was on Philae’s side that day. Had the trajectory of the bounce(s) been a few kilometres too high, and/or had Philae’s harpoons tried to pierce into comet 67P's harder-than-expected icy subsurface, Philae might have not made history.

On 15 November, the 500m km distance between Philae and the Sun became a little too long to handle. Soon after the champagne popped upon Philae's landing, its batteries began rapidly depleting because there was not enough sunlight needed to recharge them.

The engineers of European Space Agency (ESA) were, behind the smiles, all too aware of this, and before its termination, commanded Philae to rotate enough to get one of its solar panels into sunlight. It helped. Like a hedgehog with a belly swollen with food, it protected itself from the cold winter months ahead, by going into hibernation.

The hope was as the comet rotates towards the Sun, Philae would get enough solar energy through its panels to wake as the Sun rises. 

On Saturday at 20:28 UTC, at a distance from the Sun of about 200m km, Philae woke up! The signal from the lander (via Rosetta) was received by the European Space Operation Centre. Philae will make its closest encounter to the Sun on 13 August.  

"Philae is doing very well: It has an operating temperature of -35ºC and has 24 Watts available," explained DLR Philae Project Manager Dr Stephan Ulamec. "The lander is ready for operations."

According to ESA, Philae "spoke" with its team on ground for 85 seconds, via Rosetta, in the first contact since going into hibernation in November. When analysing the status data, it became clear to the ESA team that Philae also must have been awake earlier: "We have also received historical data – so far, however, the lander had not been able to contact us earlier," Ulamec added.

Due to the ESA astronomers' unwavering resilience, the Rosetta mission is the first ever to orbit a comet. Philae is the first lander to touch down on a cometary surface, and the first to wake from slumber on a speeding comet.

The scenes on comet 67P last November filled viewers with joy and fear – from Philae landing on the comet, to Philae bouncing off the comet due to the malfunctioned harpoons and consequently losing signal with Rosetta mission control. 

When Professor Mark McCaughrean, ESA’s Senior Science Adviser, heard Philae had woken up, it was half past ten at night and he and his colleagues couldn't sleep because of the excitement, he tells me. When the word finally got out to the media, the public went “nuts”, he adds.

The scientists are now waiting for the next contact with Philae. More than 8,000 data packets remain in Philae’s mass memory that will give the DLR team information on what happened to the lander in the past few days on the comet.

For now, Philae’s health will be examined. New data is expected to be sent which will hopefully include the exact location of Philae. That’ll give engineers the best methods to deal with the lander’s orientation, as well as to continue the Rosetta mission – a mission in which its prime objective is to understand the origin and evolution of the Solar System.

For more updates and current info, follow the ESA's Rosetta blog.

Tosin Thompson writes about science and was the New Statesman's 2015 Wellcome Trust Scholar. 

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.