The image of the Martian surface that confirmed the survival of Beagle2. Image: HiRISE/NASA/Leicester
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ESA's elusive Mars lander Beagle2 discovered - but how?

Eureka! We've found Beagle2 – now, where did Philae go?

Landing a spacecraft on a celestial body, whether it be the moon, Mars or a comet, is not easy. The European Space Agency found out the hard way in 2003 when its robot Beagle2, which was supposed to send back a signal after landing on Mars, didn’t do so.

But more than a decade after it went missing, the UK Space Agency has announced that the Beagle2, the elusive lander, has been re-discovered.

Beagle2 was ejected from the Mars Express spacecraft on 19 December 2003, and was scheduled to land on 25 December. The landing had Beagle2 protected by inflated airbags, which would be released from the lander and roll away before deflating. Beagle2 would then deploy its solar panels, before communicating with orbiting craft. Unfortunately, no signal was received, and after desperate attempts to communicate with Beagle2, it was sadly concluded that the lander had been lost.

The subsequent inquiry found that the most likely causes of the loss were either a problem with the Entry, Descent and Landing System (EDLS) or sheer bad luck. It now looks as though the EDLS worked – so that leaves bad luck:



Illustration: UKSA


The images that have sparked the news come from the HiRise camera on board NASA’s Mars Reconnaissance Oriter. This is an instrument which is able to take very high resolution images of Mars’ surface. The scientists leading the search for the missing Beagle2 were looking for “something that wasn’t red, and wasn’t a pointy rock”. Given that this doesn’t narrow the field down very much, it is testament to the amazing perseverance and talents of the individuals concerned that they have managed to locate the lander.

It is poignant that the information comes at this time – Colin Pillinger was very much the driving force behind Beagle2, and one of the leaders of the Rosetta mission. His premature death last year deprived the scientific community of one of its most charismatic members. How he would have gloried in the re-discovery of Beagle2.

In contrast to the finding of Beagle2 comes news of another of ESA’s landers: Philae. Getting Rosetta spacecraft to drop Philae was an exciting and nerve-wracking time – the lander successfully sent an arrival signal, but subsequent information showed that Philae hadn’t landed where it was supposed to.

Since the mid-November landing, there have been several possible sightings of Philae from cameras on-board Rosetta. But none has been confirmed as the lander. Rosetta is continuing its science mission – which means that it has moved further away from the nucleus of comet 67P Churyumov-Gerasimenko. It is now taking wider-field images of the comet’s nucleus, to search for signs of developing surface activity, rather than the more narrow, specific area images that were being acquired in the search for Philae.

Even though the exact location of Philae is unknown, the lander is not lost. It is misplaced, and there is hope that when Rosetta next approaches close to the nucleus, in mid-February, it will once again be able to resume scanning for its delinquent child.

And what of ESA’s third lander – the hugely successful Huygens spacecraft? This is also celebrating its anniversary. It landed on Saturn’s moon, Titan, in January 2005. It did everything that was asked of it, landed where it was supposed to land, acquired the data it was supposed to acquire, and then, on time and with no fuss, quietly went to sleep. A lesson for other landers to learn?

So if you kept score, ESA Landers: Mission accomplished 1, Lost 1, Found 1.The Conversation

This article was originally published on The Conversation. Read the original article.

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Don’t shoot the messenger: are social media giants really “consciously failing” to tackle extremism?

MPs today accused social media companies of failing to combat terrorism, but just how accurate is this claim? 

Today’s home affairs committee report, which said that internet giants such as Twitter, Facebook, and YouTube are “consciously failing” to combat extremism, was criticised by terrorism experts almost immediately.

“Blaming Facebook, Google or Twitter for this phenomenon is quite simplistic, and I'd even say misleading,” Professor Peter Neumann, an expert on radicalisation from Kings College London, told the BBC.

“Social media companies are doing a lot more now than they used to - no doubt because of public pressure,” he went on. The report, however, labels the 14 million videos Google have removed in the last two years, and the 125,000 accounts Twitter has suspended in the last one, a “drop in the ocean”.

It didn’t take long for the sites involved to refute the claims, which follow a 12-month inquiry on radicalisation. A Facebook spokesperson said they deal “swiftly and robustly with reports of terrorism-related content”, whilst YouTube said they take their role in combating the spread of extremism “very seriously”. This time last week, Twitter announced that they’d suspended 235,000 accounts for promoting terrorism in the last six months, which is incidentally after the committee stopped counting in February.

When it comes to numbers, it’s difficult to determine what is and isn’t enough. There is no magical number of Terrorists On The Internet that experts can compare the number of deletions to. But it’s also important to judge the companies’ efforts within the realm of what is actually possible.

“The argument is that because Facebook and Twitter are very good at taking down copyright claims they should be better at tackling extremism,” says Jamie Bartlett, Director of the Centre for the Analysis of Social Media at Demos.

“But in those cases you are given a hashed file by the copyright holder and they say: ‘Find this file on your database and remove it please’. This is very different from extremism. You’re talking about complicated nuanced linguistic patterns each of which are usually unique, and are very hard for an algorithm to determine.”

Bartlett explains that a large team of people would have to work on building this algorithm by trawling through cases of extremist language, which, as Thangam Debonnaire learned this month, even humans can struggle to identify.  

“The problem is when you’re dealing with linguistic patterns even the best algorithms work at 70 per cent accuracy. You’d have so many false positives, and you’d end up needing to have another huge team of people that would be checking all of it. It’s such a much harder task than people think.”

Finding and deleting terrorist content is also only half of the battle. When it comes to videos and images, thousands of people could have downloaded them before they were deleted. During his research, Bartlett has also discovered that when one extremist account is deleted, another inevitably pops up in its place.

“Censorship is close to impossible,” he wrote in a Medium post in February. “I’ve been taking a look at how ISIL are using Twitter. I found one user name, @xcxcx162, who had no less than twenty-one versions of his name, all lined up and ready to use (@xcxcx1627; @xcxcx1628, @xcxcx1629, and so on).”

Beneath all this, there might be another, fundamental flaw in the report’s assumptions. Demos argue that there is no firm evidence that online material actually radicalises people, and that much of the material extremists view and share is often from mainstream news outlets.

But even if total censorship was possible, that doesn’t necessarily make it desirable. Bartlett argues that deleting extreme content would diminish our critical faculties, and that exposing people to it allows them to see for themselves that terrorists are “narcissistic, murderous, thuggish, irreligious brutes.” Complete censorship would also ruin social media for innocent people.

“All the big social media platforms operate on a very important principal, which is that they are not responsible for the content that is placed on their platforms,” he says. “It rests with the user because if they were legally responsible for everything that’s on their platform – and this is a legal ruling in the US – they would have to check every single thing before it was posted. Given that Facebook deals with billions of posts a day that would be the end of the entire social media infrastructure.

“That’s the kind of trade off we’d be talking about here. The benefits of those platforms are considerable and you’d be punishing a lot of innocent people.”

No one is denying that social media companies should do as much as they can to tackle terrorism. Bartlett thinks that platforms can do more to remove information under warrant or hand over data when the police require it, and making online policing 24/7 is an important development “because terrorists do not work 9 to 5”. At the end of the day, however, it’s important for the government to accept technological limitations.

“Censorship of the internet is only going to get harder and harder,” he says. “Our best hope is that people are critical and discerning and that is where I would like the effort to be.” 

Amelia Tait is a technology and digital culture writer at the New Statesman.