Test image from Gaia: Slightly shaky to start with, but it’ll get there. (Image: ESA/DPAC/Airbus DS)
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Largest ever space camera is ready to map a billion stars

The European Space Agency's Gaia telescope is so powerful, it see stars with power akin to measuring the width of a human hair at a distance of 500 km.

After its successful launch in December, the European Space Agency’s (ESA) Gaia has now taken up its position in space and is ready to survey the skies. With the help of two onboard telescopes focused onto the largest ever space camera, Gaia is estimated to catalogue nearly one billion stars in its 5-year mission.

Like Hipparcos before it, ESA’s Gaia will map stars in the Milky Way. It will do this by measuring the brightest billion objects and determine their three-dimensional distribution and velocities. It also has the ability to measure the temperature, mass, and chemical composition of these billion objects.

Gaia will be able to discern objects up to 400,000 times dimmer than those visible to the naked eye. The positional accuracy of its measurements are akin to measuring the width of a human hair at a distance of 500 km.

The process will involve scanning each part of the sky an average of 70 times over its five-year mission lifetime, which means scanning the entire sky twice every 63 days, once through each of the two telescopes, making it a powerful tool for spotting time-evolving phenomena such as binary systems, supernovae, and exoplanets. Compared to Hipparcos, Gaia will be able to measure 500 times the number of stars, extending to objects 1000 times dimmer than the dimmest that Hipparcos could catalogue.

The technology that makes this possible is the largest camera ever launched into space – 940 million pixels. That is why a lot of effort before launch was on figuring out exactly how to get the huge amount of data Gaia will produce back down to Earth.

When a picture is taken a number of charged-coupled devices (CCDs) – the stuff most digital camera sensors are made off – are dedicated to spotting objects before they fall onto the main focal plane. This allows the instrument to track the objects as they pass and only retain small regions around the object, reducing the file-size needed to be sent to Earth. In five years it will send only 100 TB of data. Once the data arrives to Earth, there is a system in place to analyse the data and distribute alerts to ground-based observatories if anything quickly evolving and potentially interesting is spotted, such as supernovae.

The catalogue produced by Gaia is expected to contribute to many areas of astrophysics, multiply our database of exotic objects such as exoplanets, white and brown dwarfs, and supernovae many-fold, contribute to more precise measurements of General Relativity, help to constrain the measurements of the presence and location of dark matter, and give us more accurate information about our galactic neighbourhood and its evolution.

Gaia was successfully launched on 19 December. After a month’s transit, it is now in orbit at about 1.5 million km away from Earth. By virtue of its position opposite the Sun from the Earth and its large sunshield, it will be able to see objects as close as 45 degrees from the Sun, allowing it to spot asteroids with orbits that lie between the Earth and the Sun, which are candidates for Earth collision, and very difficult to observe from the ground.

Staff on the ground are conducting in-orbit testing, during which the exact orbital parameters are determined, and all systems are tested for performance. Calibration images have been obtained, and the ground team is working on procedures to resolve a few remaining issues, such as reducing contamination on the CCDs and dealing with sunlight diffracted around the sun-shield.

Beyond the alert system allowing quick ground-based follow up, the first proper Gaia catalogue will take two years to complete and will be made available to the wider scientific community. Following this, new iterations will be issued about once a year, which will add more precisely determined characteristics of these objects. It is expected that Gaia’s database will have many new discoveries waiting to be mined from it, fuelling astronomers for decades to come.

Ben Dryer has received funding from the UK Space Agency to perform Gaia data analysis.

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

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How hackers held the NHS to ransom

NHS staff found their computer screens repleaced by a padlock and a demand for money. Eerily, a junior doctor warned about such an attack days earlier. 

On Friday, doctors at Whipps Cross Hospital, east London, logged into their computers, but a strange red screen popped up. Next to a giant padlock, a message said the files on the computer had been encrypted, and would be lost forever unless $300 was sent to a Bitcoin account – a virtual currency that cannot be traced. The price doubled if the money wasn’t sent within six days. Digital clocks were counting down the time.

It was soon revealed Barts Health Trust, which runs the hospital, had been hit by ransomware, a type of malicious software that hijacks computer systems until money is paid. It was one of 48 trusts in England and 13 in Scotland affected, as well as a handful of GP practices. News reports soon broke of companies in other countries hit. It affected 200,000 victims in 150 countries, according to Europol. This included the Russian Interior Ministry, Fedex, Nissan, Vodafone and Telefonica. It is thought to be the biggest outbreak of ransomware in history.

Trusts worked all through the weekend and are now back to business as usual. But the attack revealed how easy it is to bring a hospital to its knees. Patients are rightly questioning if their medical records are safe. Others fear hackers may strike again and attack other vital systems. Defence minister Michael Fallon was forced to confirm that the Trident nuclear submarines could not be hacked.

So how did this happen? The virus, called WannaCry or WannaDecrypt0r, was an old piece of ransomware that had gained a superpower. It had been combined with a tool called EternalBlue which was developed by US National Security Agency spies and dumped on the dark web by a criminal group called Shadow Brokers. Computers become infected with ransomware when somebody clicks on a dodgy link or downloads a booby-trapped PDF, but normally another person has to be fooled for it to harm a different computer. EternalBlue meant the virus could cascade between machines within a network. It could copy itself over and over, moving from one vulnerable computer to the next, spreading like the plague. Experts cannot trace who caused it, whether a criminal gang or just one person in their bedroom hitting "send".

Like a real virus, it had to be quarantined. Trusts had to shut down computers and scan them to make sure they were bug-free. Doctors – not used to writing anything but their signature – had to go back to pen and paper. But no computers meant they couldn’t access appointments, referral letters, blood tests results or X-rays. In some hospitals computer systems controlled the phones and doors. Many declared a major incident, flagging up that they needed help. In Barts Health NHS Trust, ambulances were directed away from three A&E departments and non-urgent operations were cancelled.

The tragedy is that trusts had been warned of such an attack. Dr Krishna Chinthapalli, a junior doctor in London, wrote an eerily premonitory piece in the British Medical Journal just two days earlier telling hospitals they were vulnerable to ransomware hits. Such attacks had increased fourfold between 2015 and 2016, he said, with the money being paid to the criminals increased to $1bn, according to the FBI. NHS trusts had been hit before. A third reported a ransomware attack last year, with Imperial College London NHS Trust hit 19 times. None admitted to paying the ransom.

Hospitals had even been warned of this exact virus. It exploited a vulnerability in Microsoft Windows operating systems – but Microsoft had been tipped off about it and raised the red flag in March. It issued a patch – an update which would fix it and stop systems being breached this way. But this patch only worked for its latest operating systems. Around 5 per cent of NHS devices are still running the ancient Windows XP, the equivalent of a three-wheeled car. Microsoft said it would no longer create updates for it two years ago, rendering it obsolete.

There are many reasons why systems weren’t updated. Labour and the Lib Dems were quick to blame the attack on lack of Tory funding for the NHS. It is clear cost was an issue. Speaking on BBC Radio 4’s PM programme on Saturday, ex-chief of NHS Digital Kingsley Manning estimated it would take £100m a year to update systems and protect trusts against cyber attacks. Even if that money was granted, there is no guarantee cash-strapped trusts would ringfence it for IT; they may use it to plug holes elsewhere.

Yet even with the money to do so updating systems and applying patches in hospitals is genuinely tricky. There is no NHS-wide computer system – each trust has its own mix of software, evolved due to historical quirk. New software or machines may be coded with specific instructions to help them run. Changing the operating system could stop them working – affecting patient care. While other organisations might have time to do updates, hospital systems have to be up and running 24 hours a day, seven days a week. In small hospitals, it’s a man in a van manually updating each computer.

Some experts believe these are just excuses; that good digital hygiene kept most trusts in the UK safe. "You fix vulnerabilities in computers like you wash your hands after going to the toilet," said Professor Ross Anderson, a security engineering expert at Cambridge University. "If you don't, and patients die, excuses don't work and blame shifting must not be tolerated."

It is not known yet if any patients have died as a result of the attack, but it certainly raised fears about the safety of sensitive medical records. This particular virus got into computer files and encrypted them – turning them into gooble-de-gook and locking doctors out. Systems were breached but there have been no reports of records being extracted. Yet the scale of this attack raises fears in future the NHS could be targeted for the confidential data it holds. "If it’s vulnerable to ransomware in this way, it could be vulnerable to other attacks," said Professor Alan Woodward security expert at the University of Surrey's department of computing.

In the US, there have been examples where ransomware attacks have led to patient data being sucked out, he said. The motivation is not to embarrass people with piles or "out" women who have had an abortion, but because medical information is lucrative. It can be sold to criminals for at least $10, a price 10 times higher than can be earned by selling credit card details. Dossiers with personal identification information – known as "fullz" on the dark web – help crooks commit fraud and carry out scams. The more personal details a conman knows about you the more likely you are to fall for their hustle.

Hospital data is backed up at least hourly and three copies are kept, one offsite, so it is unlikely any medical records or significant amounts of data will have been lost – although the hack will cost the NHS millions in disruption. A British analyst, who tweets under the name Malware Tech, became an unlikely hero after accidentally finding a killswitch to stop the virus replicating. He registered a website, whose presence signalled to the virus it should stop. Yet he admits that a simple tweak of the code would create a new worm able to infect computers.

Experts warn this event could trigger a spate of copycat attacks. Hacker may turn their eyes to other public services. Dr Brian Gladman, a retired Ministry of Defence director, and ex-director of security at Nato, points out that our entire infrastructure, from the national grid, food distribution channels to the railways rely on computer systems. We now face an arms race – and criminals only have to get lucky once.

"We’re going to get more attacks and more attacks and it’s going to go on," he said. "We’ve got to pay more attention to this."

Madlen Davies is a health and science reporter at The Bureau of Investigative Journalism. She tweets @madlendavies.

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