Category Archives for "Environment"
As London’s Nato summit comes to an awkward end, the UK’s political leaders are back on the campaign trail.
The BBC’s Helen Catt explains what happened in Wednesday’s election campaigning.
British engineers have begun testing technologies that will be needed to bring samples of Martian rock to Earth.
The Airbus team is training a prototype rover to recognise and pick up small cylinders off the ground.
It’s a rehearsal for a key part of a multi-billion-dollar project now being put together by the US and European space agencies – Nasa and Esa.
Returning rock and dust materials to Earth laboratories will be the best way to confirm if life exists on Mars.
It is, though, going to take more than a decade to achieve.
The small tubes – about the size of whiteboard markers – being manipulated by the Airbus prototype represent the Martian samples.
The idea is that these will have been selected, packaged and cached on the surface of the Red Planet at various locations by the Americans’ next big rover, which launches in seven months’ time.
It would then be the job of a later European robot, launching in 2026, to run around and pick up the cylinders. This “fetch rover” would deliver the tubes to a handling station, from where they could be despatched to Earth.
They would arrive home in 2031.
At Airbus’s Stevenage facility, they’ve built a “Mars yard” to simulate the Red Planet’s surface. It’s here that robots can be put through their paces on the sort of terrain they might encounter on Earth’s near neighbour.
Right now, engineers have got a dummy rover practising the business of retrieving packaged rock samples. And, yes, the stand-ins really are whiteboard markers.
A vision-based software system directs a robot arm and claw to move into position over a cylinder. Very slowly, the mechanism reaches down and grabs its target.
The exercise works extremely well, even when the tubes are partially buried to mimic the aftermath of a Martian dust storm. But a sandpit in southern England is not quite Mars, where temperatures can be excruciatingly cold and the environment is bombarded with radiation from space. The eventual “flight model” will need to be super-robust.
The Airbus engineers are confident, however. They have just completed construction of Esa’s Rosalind Franklin rover, which will be heading to Mars in July on a separate mission. They’ll take the lessons learned from that vehicle into the development of the fetch rover.
“We’ve got a wealth of experience here in Stevenage,” said engineering manager Adam Camilletti.
“We’ve learned about how to design mechanisms, structures, electronics, overall systems, software autonomy – for working on Mars. We know the Martian environment; we know how to make things robust. And so we’re going to use all that experience and expertise to make sure that ‘Sample Fetch Rover’ is an optimal design,” he told BBC News.
Last week, Europe’s research ministers approved a near-€600m (£515m;$660m) budget for the robotic exploration of Mars. It will enable Esa to push forward on the designs, not just for the fetch rover but for the other European elements in the project. These include a satellite to carry the samples from Mars orbit back to Earth.
America has already funded and built next year’s rover which will be sent to find the rock samples. But it is expected shortly to put in place a parallel funding stream to progress its other contributions.
These would include a landing system and processing station. This large mechanism would release the fetch rover on its quest and then handle the retrieved sample canisters, loading them into a rocket that could then head skyward to meet up with the European satellite.
“Nobody’s ever tried something this challenging before,” said Mr Camilletti. “We’ve returned samples from space before but I don’t think you’ll find a project that has so many different spacecraft with such an ambitious science return. There’s been nothing comparable.”
The maker of League of Legends has agreed to pay a reported $10m (£8m) to settle a broad gender discrimination case.
Riot Games will pay the money to about a 1,000 female members of staff dating back to 2014, a US newspaper reports.
The legal action against the company was started by two women who filed the lawsuit in November 2018.
Riot Games always maintained it was “committed” to creating an environment “where all Rioters thrive.”
It’s estimated that the multi-million pound settlement will be divided among women who have been employed by Riot Games from November 2014 until the date the settlement was finalised.
League of Legends is one of the world’s most popular multiplayer games and attracts large audiences to its e-sports competitions.
Players assume the role of an unseen “summoner” that controls a “champion” and battle against a team of other players or computer-controlled characters.
A Riot spokesman, Joe Hixson, told the LA Times that the company was pleased to have a settlement that resolved the lawsuit, calling it an important step that demonstrates their commitment to creating an “inclusive environment for the industry’s best talent.”
Riot Games – based in Los Angeles – became the focus of complaints about alleged gender bias late last year after it was announced two female members of staff were launching legal action.
It was led by Melanie McCracken – an internal communications specialist who has worked at the company since 2013, and Jessica Negron – a content editor who quit in 2017 after being employed for two years.
The settlement, which comes with the promise of internal culture change, has yet to be approved by the court.
A 2018 investigation by the LA Times and the news website Kotaku, claimed Riot Games fostered an alleged “bro culture”.
The game publisher was accused of fostering an environment where female workers were sexually objectified.
Their complaint – which was shared online by Kotaku in November 2018 – made specific claims.
These included that female workers had been sexually objectified, with an email chain rating the company’s “hottest women employees”, and that female staff had been belittled by supervisors whose alleged comments included: “Her kids and husband must really miss her while she was at work,” and: “She’s shrill”.
In a statement released in August Riot Games said it had since made steps to ensure a safe and comfortable working environment for all its staff.
“We are grateful for every Rioter who has come forward with their concerns and believe this resolution is fair for everyone involved,” said Nicolo Laurent, CEO of Riot Games.
“With this agreement, we are honoring our commitment to find the best and most expeditious way for all Rioters, and Riot, to move forward and heal.
“Over the past year, we’ve made substantial progress toward evolving our culture and will continue to pursue this work as we strive to be the most inclusive company in gaming.”
The future of electric cars may depend on mining critically important metals on the ocean floor.
That’s the view of the engineer leading a major European investigation into new sources of key elements.
Demand is soaring for the metal cobalt – an essential ingredient in batteries and abundant in rocks on the seabed.
Laurens de Jonge, who’s running the EU project, says the transition to electric cars means “we need those resources”.
He was speaking during a unique set of underwater experiments designed to assess the impact of extracting rocks from the ocean floor.
In calm waters 15km off the coast of Malaga in southern Spain, a prototype mining machine was lowered to the seabed and ‘driven’ by remote control.
Cameras attached to the Apollo II machine recorded its progress and, crucially, monitored how the aluminium tracks stirred up clouds of sand and silt as they advanced.
An array of instruments was positioned nearby to measure how far these clouds were carried on the currents – the risk of seabed mining smothering marine life over a wide area is one of the biggest concerns.
It’s hard to visualise, but imagine opencast mining taking place at the bottom of the ocean, where huge remote-controlled machines would excavate rocks from the seabed and pump them up to the surface.
The concept has been talked about for decades, but until now it’s been thought too difficult to operate in the high-pressure, pitch-black conditions as much as 5km deep.
Now the technology is advancing to the point where dozens of government and private ventures are weighing up the potential for mines on the ocean floor.
The short answer: demand. The rocks of the seabed are far richer in valuable metals than those on land and there’s a growing clamour to get at them.
Billions of potato-sized rocks known as “nodules” litter the abyssal plains of the Pacific and other oceans and many are brimming with cobalt, suddenly highly sought after as the boom in the production of batteries gathers pace.
At the moment, most of the world’s cobalt is mined in the Democratic Republic of Congo where for years there’ve been allegations of child labour, environmental damage and widespread corruption.
Expanding production there is not straightforward which is leading mining companies to weigh the potential advantages of cobalt on the seabed.
Laurens de Jonge, who’s in charge of the EU project, known as Blue Nodules, said: “It’s not difficult to access – you don’t have to go deep into tropical forests or deep into mines.
“It’s readily available on the seafloor, it’s almost like potato harvesting only 5km deep in the ocean.”
And he says society faces a choice: there may in future be alternative ways of making batteries for electric cars – and some manufacturers are exploring them – but current technology requires cobalt.
“If you want to make a fast change, you need cobalt quick and you need a lot of it – if you want to make a lot of batteries you need the resources to do that.”
His view is backed by a group of leading scientists at London’s Natural History Museum and other institutions.
They recently calculated that meeting the UK’s targets for electric cars by 2050 would require nearly twice the world’s current output of cobalt.
No one can be entirely sure, which makes the research off Spain highly relevant.
It’s widely accepted that whatever is in the path of the mining machines will be destroyed – there’s no argument about that.
But what’s uncertain is how far the damage will reach, in particular the size of the plumes of silt and sand churned up and the distance they will travel, potentially endangering marine life far beyond the mining site.
The chief scientist on board, Henko de Stigter of the Dutch marine research institute NIOZ, points out that life in the deep Pacific – where mining is likely to start first – has adapted to the usually “crystal clear conditions”.
So for any organisms feeding by filter, waters that are suddenly filled with stirred-up sediment would be threatening.
“Many species are unknown or not described, and let alone do we know how they will respond to this activity – we can only estimate.”
And Dr de Stigter warned of the danger of doing to the oceans what humanity has done to the land.
“With every new human activity it’s often difficult to foresee all the consequences of that in the long term.
“What is new here is that we are entering an environment that is almost completely untouched.”
Ralf Langeler thinks so. He’s the engineer in charge of the Apollo II mining machine and he believes the design will minimise any impacts.
Like Laurens de Jonge, he works for the Dutch marine engineering giant Royal IHC and he says his technology can help reduce the environmental effects.
The machine is meant to cut a very shallow slice into the top 6-10cm of the seabed, lifting the nodules. Its tracks are made with lightweight aluminium to avoid sinking too far into the surface.
Silt and sand stirred up by the extraction process should then be channelled into special vents at the rear of the machine and released in a narrow stream, to try to avoid the plume spreading too far.
“We’ll always change the environment, that’s for sure,” Ralf says, “but that’s the same with onshore mining and our purpose is to minimise the impact.”
I ask him if deep sea mining is now a realistic prospect.
“One day it’s going to happen, especially with the rising demand for special metals – and they’re there on the sea floor.”
Mining in territorial waters can be approved by an individual government.
That happened a decade ago when Papua New Guinea gave the go-ahead to a Canadian company, Nautilus Minerals, to mine gold and copper from hydrothermal vents in the Bismarck Sea.
Since then the project has been repeatedly delayed as the company ran short of funds and the prime minister of PNG called for a 10-year moratorium on deep sea mining.
A Nautilus Minerals representative has told me that the company is being restructured and that they remain hopeful of starting to mine.
Meanwhile, nearly 30 other ventures are eyeing areas of ocean floor beyond national waters, and these are regulated by a UN body, the International Seabed Authority (ISA).
It has issued licences for exploration and is due next year to publish the rules that would govern future mining.
The EU’s Blue Nodules project involves a host of different institutions and countries.
The vessel used for the underwater research off Spain, the Sarmiento de Gamboa, is operated by CSIC, the Spanish National Research Council.
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Atmospheric concentrations of carbon dioxide and other greenhouse gases once again reached new highs in 2018.
The World Meteorological Organization (WMO) says the increase in CO2 was just above the average rise recorded over the last decade.
Levels of other warming gases, such as methane and nitrous oxide, have also surged by above average amounts.
Since 1990 there’s been an increase of 43% in the warming effect on the climate of long lived greenhouse gases.
The WMO report looks at concentrations of warming gases in the atmosphere rather than just emissions.
The difference between the two is that emissions refer to the amount of gases that go up into the atmosphere from the use of fossil fuels, such as burning coal for electricity and from deforestation.
Concentrations are what’s left in the air after a complex series of interactions between the atmosphere, the oceans, the forests and the land. About a quarter of all carbon emissions are absorbed by the seas, and a similar amount by land and trees.
Using data from monitoring stations in the Arctic and all over the world, researchers say that in 2018 concentrations of CO2 reached 407.8 parts per million (ppm), up from 405.5ppm a year previously.
This increase was above the average for the last 10 years and is 147% of the “pre-industrial” level in 1750.
The WMO also records concentrations of other warming gases, including methane and nitrous oxide. About 40% of the methane emitted into the air comes from natural sources, such as wetlands, with 60% from human activities, including cattle farming, rice cultivation and landfill dumps.
Methane is now at 259% of the pre-industrial level and the increase seen over the past year was higher than both the previous annual rate and the average over the past 10 years.
Nitrous oxide is emitted from natural and human sources, including from the oceans and from fertiliser-use in farming. According to the WMO, it is now at 123% of the levels that existed in 1750.
Last year’s increase in concentrations of the gas, which can also harm the ozone layer, was bigger than the previous 12 months and higher than the average of the past decade.
What concerns scientists is the overall warming impact of all these increasing concentrations. Known as total radiative forcing, this effect has increased by 43% since 1990, and is not showing any indication of stopping.
“There is no sign of a slowdown, let alone a decline, in greenhouse gases concentration in the atmosphere despite all the commitments under the Paris agreement on climate change,” said WMO Secretary-General Petteri Taalas.
“We need to translate the commitments into action and increase the level of ambition for the sake of the future welfare of mankind,” he added.
“It is worth recalling that the last time the Earth experienced a comparable concentration of CO2 was three to five million years ago. Back then, the temperature was 2-3C warmer, sea level was 10-20m higher than now,” said Mr Taalas.
The UN Environment Programme will report shortly on the gap between what actions countries are taking to cut carbon and what needs to be done to keep under the temperature targets agreed in the Paris climate pact.
Preliminary findings from this study, published during the UN Secretary General’s special climate summit last September, indicated that emissions continued to rise during 2018.
Both reports will help inform delegates from almost 200 countries who will meet in Madrid next week for COP25, the annual round of international climate talks.
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A critical 12 months in the battle against rising temperatures begins in Madrid this week, as UN delegates gather for key talks.
The 25th Conference of the Parties, or COP, will see negotiators from almost 200 countries in attendance.
Ahead of the meeting the UN secretary general has warned that the world is at the point of no return.
António Guterres said the global response to date has been “utterly inadequate”.
The conference takes place amid a welter of bad news on climate change in recent days.
The World Meteorological Organisation announced that greenhouse gas concentrations reached their highest recorded level in 2018.
The UN Environment Programme showed that there’s a huge gap between the plans that governments currently have on the table to cut emissions and what’s needed to keep under 1.5C. Keeping to that guardrail will need a five-fold increase in the carbon cutting ambitions of countries.
The UN Secretary General warned delegates ahead of the meeting “the point of no return was no longer over the horizon”.
“We simply have to stop digging and drilling and take advantage of the vast possibilities offered by renewable energy and nature-based solutions,” Mr Guterres said.
As well as demanding that the negotiators increase their level of carbon cutting ambition at this meeting, Mr Guterres announced that the Governor of the Bank of England Mark Carney will take on the role of UN Special Envoy on climate action and climate finance.
Yes, this annual event, the Conference of the Parties or COP was due to take place in the Chilean capital Santiago this year. It was cancelled by President Sebastián Piñera due to ongoing civil unrest in the country.
After a brief flurry of diplomatic activity, Spain said they would step into the void and host the conference, with Chile still leading the diplomatic negotiations.
The Spanish argue that it is critical to support a UN process that depends on global co-operation in the face of rising nationalism around the world.
“COP25 will reaffirm that multilateralism is the best tool to solve global challenges such as climate change,” said Spain’s minister for the ecological transition Teresa Ribera.
“Neither the UN nor the international community have let the climate agenda fall, despite the challenges to organise this event, because this is a vital moment to drive implementation and action. Spain immediately offered to organise the summit in record time. There is no turning back.”
The hope is that this meeting will concentrate the minds of international diplomats on the huge scale of the challenge.
Governments have promised to update their climate pledges by 2020, when the COP will be held in Glasgow.
But so far, despite the urgings of scientists, major improvements in pledges have been slow to materialise.
Many nations have aspirations to carbon neutrality in the long term, but they have been slow to put specific short-term commitments on the table.
“Some 70 countries have pledged to become carbon neutral by 2050, this must be carried on at Madrid COP,” said Sonam Wangdi, the Chair of the Least Developed Countries (LDC) group in UN climate change negotiations.
“There must be an agreement among us all to do our fair share. If it doesn’t happen in Madrid it could be too late for 2020 pledges.”
The hope for Madrid is that the meeting can avoid major bust ups and keep edging forward.
It also has to overcome two possible banana skins – loss and damage, and carbon markets.
This issue has dogged the negotiations for several years now, but the likelihood is that it will come to a head in Madrid.
Loss and damage are the impacts that can’t be prevented or adapted to by countries.
Some experts consider “loss” to apply to the complete destruction of something such as human lives, habitats and species. “Damage” refers to something that can be repaired, such as roads or buildings.
So the examples that are given are rising sea levels which can’t be prevented, or storms that are connected to rising temperatures.
Back in 2013, under pressure from developing countries, the climate talks set up a special forum to discuss loss and damage. In Madrid the delegates must decide how to progress. Poorer nations want the loss and damage to have teeth within the UN setup, and more importantly, funding.
“Everybody has to recognise that there is a need and then there must be a funding window,” said Sonam Wangdi from the LDCs.
“Once you have that, where the funding comes from is secondary, right now there is no fund.”
Rich countries fear that the whole question is a way of tying them into paying out for sea level rise and storms for centuries ahead, because the bulk of the carbon in the atmosphere comes from fossil fuels used by the developed world.
As the conference starts, 150 environmental groups including climate activists Naomi Klein and Lidy Nacpil have written to ministers calling for adequate funding for loss and damage.
They say the combination of climate disasters and debt can prove toxic for developing nations.
“The climate crisis has been causing death, despair and displacement in the global south,” said Harjeet Singh from Action Aid.
“This bullying of the countries hardest hit by climate change, by those that got rich from extracting and consuming fossil fuels, must end now.”
Hot air is in fact one of the big concerns with the question of carbon markets.
In the past richer countries have often paid for carbon reduction projects in poorer nations.
The wealthy have then been able to count the carbon saved from these projects against their own emissions.
These schemes were discredited amid accusations of fraud and “double counting” where both the poor and the rich countries counted the same emissions reduction as part of their plans.
Article six of the Paris agreement set out to reform these carbon markets, recognising that if they were transparent and effective they could really help to raise ambitions.
Discussions on how the new arrangements would work were due to be completed in Katowice at the COP last year but they ran into real problems. Brazil resisted all attempts to curtail double counting. Other countries wanted to carry forward carbon credits from older schemes.
Some also want to be able to sell or carry forward credits if they overachieve on their existing carbon cutting plans, which observers feel would encourage countries to set a low bar in terms of commitments.
Experts often call these types of credits “hot air” as they are more an accounting exercise than a real reduction in carbon dioxide.
The amount of “hot air” is huge, running into billions of tonnes of carbon. Experts fear that these could undermine the integrity of the Paris pact if they are allowed to continue.
“We believe that these markets will have an impact but they must result in real reductions on the ground,” said Sonam Wangdi from the LDCs.
“The option is needed and the carbon market is one of the tools – but there needs to be environmental integrity and they need to be transparent and there needs to be real reductions there.”
Trying to get unanimous agreement between almost 200 countries on how to tackle climate change is a really big ask. The agreement that was struck in Paris in 2015 only came about after six long years of snail pace negotiations.
It was the deal that diplomats had hoped to strike in the failed Copenhagen COP in 2009.
So if the goal is that countries have new promises in place by the end of 2020, Madrid is an important snapshot of what can realistically be achieved.
Countries often tend to hold back on their pledges until they see what others are likely to do. Madrid will give a sense of whether there is a willingness from some of the larger countries, like India, China and the EU, to show leadership.
“After 30 years of advocacy and optimism, we see COP 25 as the last opportunity to take decisive action,” said Ambassador Janine Felson from Belize, the deputy chair of the Alliance of Small Island States.
“Anything short of a vastly greater commitment to emission reduction through new national plans that are consistent with our fight for a 1.5 degree world, greater momentum towards honouring outstanding 2020 climate finance commitments, a new climate finance goal suitable for achieving a 1.5 degree world and tangible support for disaster risk reduction and reconstruction in small island and developing states will signal a willingness to accept catastrophe.”
This could be the last year in which a US team will play a part in the negotiations. On 4 November President Trump sent a formal letter to the UN, which has triggered the 12-month countdown to the US pullout.
The Americans are due to leave on 4 November 2020, one day after the next US presidential election and five days ahead of the critical COP26 in Glasgow.
The US has been playing a more truculent role in recent negotiations, joining with Saudi Arabia, Kuwait and Russia to prevent the conference welcoming a key IPCC report on how the world can keep temperatures under 1.5C this century.
Over the past couple of years the US has also supported side events promoting coal and will likely continue to do so in the future.
Even if they do withdraw completely next year, that will only be from the Paris agreement part of the negotiations. The US will still be party to the UN climate convention. It is unlikely they will stop sending teams to the conferences.
Just a year ago, Greta Thunberg attended the Katowice COP as a relatively unknown Swedish student who was taking direct action in striking from school for the climate. A year later and she has become a global icon who can get a standing ovation from diplomats by calling out their hypocrisy on rising temperatures.
Greta’s dedication to the cause has been enhanced by her decision to cross the Atlantic in a yacht to attend the Santiago meeting. Now she is on another boat on her way back to Madrid. She is due to arrive a few days after the start. Her participation and her speech will likely make headlines around the world.
Conferences like the COP are rooted in a traditional UN diplomatic that requires a unanimous agreement on steps forward. While environmental campaigners and others can observe, there is limited input from young people, school strikers and other voices.
Nordic countries are attempting to do something different this year with ministers from Sweden, Finland and Iceland inviting five young people from different countries to take part in discussions with politicians and report back from COP25.
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TikTok has announced it is changing its virtual gifts policy as a response to a BBC investigation.
In July, the BBC revealed how children and teenagers were being pressured to buy digital items for “celebrities” on the platform.
In some cases, fans bought gifts worth hundreds of pounds – which could be swapped back for cash – in exchange for phone numbers and private messages.
TikTok said it is now limiting the activity to those aged 18 and above.
The move will restrict a revenue stream for the Chinese-owned company, which profited from the transactions. But it should also help it to address parents’ concerns about whether its platform is a safe place for youngsters.
“Our updated policy will only allow those aged 18 and over to purchase, send, or receive virtual gifts,” said TikTok in a statement.
“We are making these changes to foster a safe environment where users of all ages can enjoy a live-stream without encountering misuse, such as any pressure to send virtual gifts.”
About one billion people use the international version of TikTok, which uses a different library of user-generated content to the China-focused version, known as Douyin.
The company said the changes would be rolled out globally over the next three weeks.
Scientists from the University of Manchester are creating a blueprint to help bands and pop stars to perform live and tour the world without contributing to climate change.
It’s after the Tyndall Centre for Climate Change Research were approached by the group Massive Attack who say they want to help find solutions to the climate crisis.
The findings will be shared with musicians from across the industry and, it’s hoped, will inspire millions of fans to live more sustainably.
Massive Attack have spent a lot of 2019 with the environmental campaign group Extinction Rebellion, even playing a set at one of their protests in London in April.
Robert del Naja, aka 3D, told the BBC he felt conflicted because of how his career has contributed to climate change.
“[As musicians] we have enjoyed a high carbon lifestyle. But as a society we’ve all existed in a fossil fuel economy for a long time and had very little choice in that.
“The challenge now is to not only make personal sacrifices, but to insist on the systemic change that’s needed. Business as usual is over.”
The news comes a week after Coldplay announced they would not tour with their latest album for environmental reasons.
Meanwhile, Billie Eilish is offering fans a chance to earn tickets to her next tour by fighting climate change and there’ll be eco-villages at each concert where fans can learn more about the issues facing the planet.
What will the scientists be looking at?
This new research will look at all aspects of touring and how its carbon footprint can be reduced to zero, or as close to zero as possible.
It’s not looking simply at balancing out emissions from concerts by planting trees for removing carbon dioxide from the air – a process known as carbon offsetting.
Instead, researchers will look at how to reduce the amount of energy used during concerts and in moving musicians, crews and sets between different venues and cities, as well as the impact audiences have.
Tyndall Manchester’s Director, Prof Carly McLachlan, says they’ll be looking at where switches can be made to renewable energy sources, how to reduce the amount of energy being consumed but also thinking about how touring could be different.
“It is a high carbon sector and we need to try and tackle that, because every sector has to be part of the transition to a low-carbon economy.”
It’s not yet known what impact, if any, changing the way tours are put on will have on ticket prices, routes or number of concerts.
Just how bad is live music for the environment?
Musicians are often criticised when they speak out about climate change and carbon because they have high carbon lifestyles.
Promoting albums and performing in cities around the world means artists and their teams fly a lot.
Then there are the carbon emissions from tour buses, from moving sets, from making merchandise, on top of the energy needed for things like lighting and sound.
Recent figures suggest that live music generates 405,000 tonnes of greenhouse gas emissions in the UK every year.
Prof Carly McLachlan says music and art and culture are a “really beautiful part of what it is to be human”. “If this is something we really value in our lives, we need to make sure we can do it in a way that has reduced impact.”
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Data sent back by the two Voyager spacecraft have shed new light on the structure of the Solar System.
Forty-two years after they were launched, the spacecraft are still going strong and exploring the outer reaches of our cosmic neighbourhood.
By analysing data sent back by the probes, scientists have worked out the shape of the vast magnetic bubble that surrounds the Sun.
The two spacecraft are now more than 10 billion miles from Earth.
Researchers detail their findings in six separate studies published in the journal Nature Astronomy.
“We had no good quantitative idea how big this bubble is that the Sun creates around itself with its solar wind – ionised plasma that’s speeding away from the Sun radially in all directions,” said Ed Stone, the longstanding project scientist for the missions.
“We certainly didn’t know that the spacecraft could live long enough to reach the edge and leave the bubble to enter interstellar space.”
The plasma consists of charged particles and gas that permeate space on both sides of the magnetic bubble, known as the heliosphere.
Measurements show that the identical probes have exited the heliosphere and entered interstellar space – the region between stars. Voyager 1 entered interstellar space in 2012, Voyager 2 crossed over late last year. The key sign in both cases was a jump in the density of plasma.
This showed that the spacecraft were passing from an environment with hot, lower density plasma characteristic of the solar wind and entering a region with the cool, higher density plasma thought to be found in interstellar space.
The boundary between the two regions is known as the heliopause.
“We saw the plasma density at the heliopause jump by a very large amount – a factor of 20, at this rather sharp boundary out there,” said Prof Don Gurnett, from the University of Iowa.
“Actually, with Voyager One we saw an even bigger jump.”
The findings suggest that the heliosphere is symmetrical, at least at the two points that the Voyager spacecraft crossed. The researchers say these points are almost at the same distance from the Sun, indicating a spherical front to the bubble – “like a blunt bullet”, according to Prof Gurnett.
The results also provide clues to the the thickness of the “heliosheath”, the outer region of the magnetic bubble. This is the point where the solar wind piles up against the approaching wind of particles in interstellar space, which Prof Gurnett likens to the effect of a snow plow on a city street.
The heliosheath appears to vary in its thickness. This is based on data showing that Voyager 1 had to travel further than its twin to reach the heliopause, where the solar wind and the interstellar wind are in balance.
Some had thought Voyager 2 would make that crossing into interstellar space first, based on models of the magnetic bubble.
“In a historical sense, the old idea that the solar wind will just be gradually whittled away as you go further into interstellar space is simply not true,” says Don Gurnett.
“We show with Voyager 2 – and previously with Voyager 1 – that there’s a distinct boundary out there. It’s just astonishing how fluids, including plasmas, form boundaries.”
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Japan’s Hayabusa-2 spacecraft has departed from a faraway asteroid and begun its year-long journey back to Earth.
The spacecraft left its orbit around Ryugu on Wednesday with samples of the asteroid in tow.
Hayabusa-2 is expected to return to Earth in late 2020, completing its successful multi-year mission.
Japan’s space agency, Jaxa, said the collected samples could shed light on the origins of the Solar System.
Hayabusa-2 first launched in 2014. Three and a half years later, it reached the asteroid Ryugu, located about 300 million km (190 million miles) from Earth.
Following its arrival in June 2018, the spacecraft made touchdowns twice, collecting data and rock samples from the Ryugu – a primitive space rock leftover from the early days of the Solar System.
The first touchdown – which happened in February – included firing a “bullet” into the rocky surface to kick up rock samples, which were then caught by the sampler horn that extends from the bottom of the spacecraft.
The second touchdown happened in July, after the Hayabusa-2 first “bombed” the asteroid to create an artificial crater. Later, it returned to land in the crater and collect the fresh rubble, including rock samples from beneath the surface.
Scientists believed these would be more pristine samples, since they would not have been exposed to the harsh environment of space. They were the first underground samples collected from an asteroid in space history.
The Hayabusa-2 is expected to return to Earth in December 2020, dropping a capsule containing the rock samples in the South Australian desert.
The yearlong return journey is much shorter than the three and a half years it took the spacecraft to reach Ryugu, thanks to the asteroid now being much closer to Earth than it was in 2014.
While asteroids are some of the oldest objects in space, Ryugu belongs to a particularly primitive type of space rock, and may contain clues about the conditions and chemistry of the early days of the Solar System – some 4.5 billion years ago.