Evidence that water was once present on Mars has been mounting for decades, and this month NASA’s Perseverance rover collected rock samples which have all but confirmed groundwater flowed on the red planet.
Mars was born with a fatal flaw that doomed it to become a barren lifeless place, according to new research: it was always too small to retain large amounts of water.
Evidence that water was once present on Mars has been mounting for decades and this month NASA’s Perseverance rover collected rock samples which have all but confirmed groundwater flowed on the red planet.
But the space agency’s scientists weren’t sure whether that water was present for tens of thousands of years or for millions of years. Now, more scientists believe they can contribute to the understanding of why that water disappeared.
Mars is ostensibly located within the “habitable zone”, a distance from the sun which is neither too hot nor too cold to support liquid surface water and thus life – but it appears to support neither at the moment.
The most popular hypothesis for why Mars is barren today is based on its lack of a magnetosphere.Advertisement
Unlike the Earth, where molten iron in the core of the planet created a protective magnetic shield around us, Mars’ magnetic field is too weak to protect its atmosphere from being stripped away by cosmic forces.
Now a study published in the Proceedings of the National Academy of Science suggests Mars was created with a fatal flaw that meant it was never going to be able to protect that atmosphere and its liquid water.
“Mars’ fate was decided from the beginning,” explained Kun Wang, an assistant professor at Washington University and senior author of the study.
“There is likely a threshold on the size requirements of rocky planets to retain enough water to enable habitability and plate tectonics, with mass exceeding that of Mars,” he explained.
Wang’s team analysed potassium isotopes on Mars, something which can be used to trace volatile elements such as water, and compared them to Earth, the moon and an asteroid called 4-Vesta.
They found there was a clear correlation between the size of the cosmic body and the presence of potassium isotopes.
As the only Martian samples available on Earth are those from meteorites, they also often function a little like capsules showing what the planet was like at different stages in its history.
“This study emphasises that there is a very limited size range for planets to have just enough but not too much water to develop a habitable surface environment,” said co-author Klaus Mezger of the Centre for Space and Habitability at the University of Bern. “These results will guide astronomers in their search for habitable exoplanets in other solar systems.”
Wang now thinks that, for planets that are within habitable zones, planetary size probably should be more emphasised and routinely considered when thinking about whether an exoplanet could support life.
“The size of an exoplanet is one of the parameters that is easiest to determine,” Wang added. “Based on size and mass, we now know whether an exoplanet is a candidate for life, because a first-order determining factor for volatile retention is size.”
Facebook: Mark Zuckerberg says claims against company are attempt to ‘paint a false picture’
His comments follow evidence from whistleblower Frances Haugen who told MPs that algorithms can be used that “take people who have mainstream interests and push them to extreme interests”.
Facebook CEO Mark Zuckerberg has said recent claims against the social media giant are an attempt to “paint a false picture of our company”.
Whistleblower Frances Haugen has told MPs that groups on the social media site can be “dangerous” because they use algorithms that “take people who have mainstream interests and push them to extreme interests”.
She said groups can become “echo chambers” that reinforce people’s opinions and gave the example that users with left-wing opinions can be pushed to the radical left, while those looking for healthy recipes can be pushed towards anorexia content.
Mr Zuckerberg’s comments came after reports on the Facebook Papers, a vast cache of internal documents, and Ms Haugen’s testimony to MPs and followed a 17% increase in the company’s net income in the July-September period to $9.19bn, buoyed by strong advertising revenue.
In a post on his Facebook page, Mr Zuckerberg said: “I believe large organizations should be scrutinized and I’d much rather live in a society where they are than one where they can’t be. Good faith criticism helps us get better.Advertisement
“But my view is that what we’re seeing is a coordinated effort to selectively use leaked documents to paint a false picture of our company.”
He added: “It makes a good soundbite to say that we don’t solve these impossible tradeoffs because we’re just focused on making money, but the reality is these questions are not primarily about our business, but about balancing difficult social values.”
His comments were mostly a repeat of what he said after Ms Haugen appeared before a US Senate subcommittee on 5 October.
Ms Haugen, a former product manager in the company’s civic integrity unit, told MPs on Monday: “One of the things that happens with groups and networks of groups is people see echo chambers that create social norms…” and that people with opposing views are “torn apart”.
“When that context is around hate you see a normalisation of hate, a normalisation of dehumanising others, and that’s what leads to violent incidents,” she added.
She also told the committee that Facebook “unquestionably” makes online hate worse, sees safety as a “cost centre”, and that “critical teams” are understaffed.
“If you make noise saying we need more help… you will not get rallied around for help because everyone is under water,” she said.
She said “engagement-based metrics” – which focus on how many people like, share or comment on a post – were a major problem on all social media sites.
She said they favoured polarised content and were “biased towards bad actors”.
“The events we’re seeing around the world, things like Myanmar and Ethiopia, those are the opening chapters because engagement-based ranking does two things: one, it prioritises and amplifies divisive and polarising extreme content and two it concentrates it,” said Ms Haugen.
Tesla worth $1trn as investors cheer deal with Hertz which has ordered 100,000 electric vehicles
Following the announcement of the deal, Tesla’s shares jumped by over 9.5% to top $995.75, making the company worth $1trn, according to Reuters.
Tesla’s market capitalisation passed $1trn on Monday after its shares surged following a deal with car rental company Hertz which has ordered 100,000 new electric vehicles from the manufacturer.
It is the largest-ever order for the firm founded by Elon Musk.
Following the announcement of the deal, Tesla’s shares jumped by over 9.5% to top $995.75, making the company worth $1trn (around £726bn), according to Reuters.
The agreement will see Hertz complete its purchases of the Tesla Model 3 cars by the end of 2022, while customers will be able to start renting Tesla’s electric vehicles through Hertz starting from next month.
The deal is likely to be worth around $4bn (£2.9bn) because each Model 3 has a base price of about $40,000 (£29,000).Advertisement
It also ranks at the top of the list of electric vehicle orders by a single firm.
By becoming a $1trn company, Tesla joins an elite group of famous firms that have already passed the mark.
The only other publicly listed companies in the US that have reached a $1trn market capitalisation so far are Apple, Amazon, Microsoft, and Alphabet, the parent company of Google.
Hertz customers will be able to access Tesla’s network of superchargers across the US and Europe – and the rental company has also pledged to install 3,000 chargers of its own by the end of next year.
“We absolutely believe that this is going to be competitive advantage for us,” acting chief executive of Hertz, Mark Fields, said of the Tesla order.
Speaking to Reuters, Mr Fields added: “We want to be a leader in mobility…Getting customers experience with electrified vehicles is an absolute priority for us.”
Hertz currently has around 430,000 to 450,000 vehicles worldwide, and has said it will work with other companies producing electric vehicles – not just Tesla. Following the latest order, Mr Fields said that electric vehicles will make up more than 20% of its global fleet.
Mr Musk’s company is currently struggling to fulfil a backlog of orders, and is suffering from supply chain issues – but experts say that the deal cements the mainstream status of electric vehicles.
Facebook under fresh pressure as whistleblower prepares to give evidence to MPs
The company has been plunged into a crisis since Frances Haugen released thousands of pages of internal research documents secretly copied before leaving her job in the firm’s civic integrity unit.
A Facebook whistleblower whose claims have rocked the social media giant has launched a fresh attack on Mark Zuckerberg, accusing him of not being willing to protect public safety.
The latest broadside by former employee Frances Haugen comes as she prepares to give evidence to MPs at Westminster.
Her intervention ramps up the pressure on the embattled $1trn (£750bn) company, which has been plunged into a crisis since she released thousands of pages of internal research documents secretly copied before leaving her job in the firm’s civic integrity unit.
It comes amid newspaper reports that workers repeatedly warned Facebook was being flooded with misinformation claiming that the 2020 US presidential election result was being rigged.
Workers reportedly believed more should have been done to tackle it.Advertisement
It has fuelled renewed concerns about Facebook’s role in the 6 January Capitol riots, in which a mob seeking to overturn the election result stormed Congress.
Separate leaked documents also reveal Facebook in India wavered in curbing hate speech and anti-Muslim content on its platform and lacked enough local language moderators to stop misinformation, which at times sparked violence.
Criticising Facebook CEO Mark Zuckerberg in a interview with The Observer newspaper, Ms Haugen said: “Right now, Mark is unaccountable.
“He has all the control.
“He has no oversight, and he has not demonstrated that he is willing to govern the company at the level that is necessary for public safety.”
She said she had leaked the documents because she realised the company would not change otherwise.
Ms Haugen made her comments ahead of facing questions from a UK parliamentary committee scrutinising the draft Online Safety Bill, which aims to regulate tech firms and social media in a bid to curb cyber abuse and threats.
She has already levelled a series allegations against the social network, saying its platforms “harm children, stoke division and weaken our democracy”, and that it refused to act because executives put profits above safety.
Ms Haugen has also accused the tech giant of being aware of the apparent harm Instagram could have on some teenagers and their body image, and said the firm had been dishonest in its public fight against hate content and misinformation by concealing research that showed it amplified such content.
Mr Zuckerberg has rejected the claims made by Ms Haugen, saying her attacks on the company were “misrepresenting” the work it does and that it “cares deeply about issues like safety, well-being and mental health”.
He added: “At the heart of these accusations is this idea that we prioritise profit over safety and well-being. That’s just not true.”
Facebook is reportedly planning to rebrand its business name in an apparent bid to distance its wider business from the string of controversies that have engulfed it in recent years.
Among its latest big ideas is the so-called metaverse, a 3D online world the firm wants to lead the way on building, in which people can meet, play and work virtually, often using virtual reality headsets.
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