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As people swoon over the 'supermoon' currently lighting up our skies you might be surprised to learn that scientists are still debating the origins of the Earth's closest companion.

This week a special edition of the journal Royal Society A is published featuring ideas about the Moon's origins discussed at a meeting held last year.

I asked Professor Alex Halliday of Oxford University's Department of Earth Sciences, who co-edited the special edition and co-wrote the introduction, about the historical quest for the truth about the Moon and how the latest theories could be put to the test…

OxSciBlog: Why has understanding the Moon’s origins been, historically, such a challenge?
Alex Halliday: The Moon is unusual compared with other moons in our Solar System. It is the largest moon relative to the size of its host planet, it is gradually moving away from Earth, and its orbit is tied to Earth's rotation with most of the angular momentum in the Moon’s motion. It also has a lower uncompressed density than that of Earth implying a smaller iron core.

We have known these things for a while and they fit to varying degrees with a number of old theories: fission (that the Moon was spun out of Earth’s interior); co-accretion (that the Moon just formed alongside Earth); and capture (that Earth captured a wandering planetary embryo into orbit).

Since samples were returned in the Apollo missions in the Sixties and Seventies five other things have become apparent:

First, the isotopic compositions of elements like oxygen and titanium are highly diverse in meteorites and hence probably radially variable within the Solar System, providing a kind of fingerprint for where atoms have been derived from. They are almost identical between the Earth and its Moon – suggesting that the material that formed the Moon came from Earth.

Second, the Moon is much more depleted in volatile elements - not just water but also in potassium for example. This suggests that either the Moon did not come from Earth, or that the process of lunar formation was hot, and somehow depleted the material in volatile elements.

Third, the Moon formed late – isotopic techniques show that the Moon formed more than 30 million years after the Solar System, whereas other Moon-sized objects should form within the first million years or so of the formation of the swirling disk that built our Solar System.

Fourth, the oldest rocks brought back by Apollo come from the Highlands (the whitish bits when you look at the Moon at night) and appear to have formed as various concentrations of crystals that floated/sank in a lunar magma ocean – suggesting a hot fiery start.

Fifth, the trace elements (such as rare earth elements) in younger lunar basalts (the dark areas on the Moon) provide evidence that they were derived by melting a deep lunar interior that itself was made of crystals that accumulated in this magma ocean – in other words the fiery magma ocean was global and extended to deep within the Moon.

All of this led to a model of a Moon origin through a massive late collision (the 'Giant Impact') between two already formed planets – the proto Earth when it was perhaps 90% formed and another smaller planet sometimes called 'Theia' that made up the remaining 10% (so about the size of Mars). Theia struck the Earth with a highly energetic glancing blow generating the angular momentum and a debris disk of hot degassed material from Earth’s outer iron depleted parts that coalesced to form a molten ball.

This idea was finally established in 1984 in a meeting in Hawaii on the origin of the Moon. Subsequently, dynamic supercomputing simulations were able to successfully generate a Moon in this fashion. This fiery ball would have originally occupied perhaps about a third of the sky at night but has been migrating further away as a now cooled Moon ever since it formed.

OSB: What are the latest ideas about how the Moon formed?
AH: The Giant Impact theory is the least worst explanation for all of the above features, but there is a problem. Those scientists developing the computer models use a technique called smoothed particle hydrodynamics and this treats the material in the proto-Earth and Theia as made up of large numbers of equally sized large fragments (the so called 'particles') that interact with each other by gravity. The source of the fragments can be traced through the simulations. Nearly all of the fragments from Theia wind up embedded in the Earth. On this basis Earth has a composition that is a mix of (say) 90% proto-Earth and 10% Theia. Very little is lost from Earth.

However, when the scientists track the proportions of the two planets that wind up forming the Moon (which is only about 1% of Earth’s mass) they are very different. In nearly all successful simulations the Moon is mainly (>50%) made up of material from Theia. This is hard to reconcile with the isotopic evidence that the Moon formed from atoms like those found in the Earth rather than in other parts of the Solar System.

Four explanations for this have been considered and the pros and cons formed the main basis for the Royal Society’s Discussion Meeting on the Origin of the Moon in September of last year, the papers from which are now published:

1) Theia formed at the same heliocentric distance as the proto Earth so that the isotopic compositions look the same: The difficulty with this comes from explaining why the two planets stayed in a stable configuration for over thirty million years before colliding.

2) Meteorites are sampling the Solar System outboard of the Earth whereas Theia came from closer in to the Sun: It could be that Theia came from an inner region of the Solar System such as in the vicinity of Venus or Mercury where isotopic compositions look the same as those of Earth. We cannot test this without samples (rock or atmosphere) that we know came from Mercury or Venus.

3) The Giant Impact was so energetic that the atoms in the Earth were able to mix and exchange with those in the disk from which the Moon formed, eliminating original differences: This works for oxygen but is harder for some elements that are more refractory like titanium.

4) The simulations are simply wrong: A new class of simulation was published in 2012 proposing a Moon-forming impact between Theia and a proto-Earth that was already spinning very fast, perhaps with a day of just two hours. In other words the angular momentum is not generated by the Giant Impact – it was already present. Under these circumstances a Moon can be generated by a head on collision with a much smaller Theia – perhaps 2% of Earth's mass – leading to a debris disk dominated by material from Earth or at least in similar proportions. The problem with this and similar models is with how to slow down the Earth-Moon system afterwards. The authors have appealed to a tidal resonance with the Sun but some argue this is unlikely to work.

OSB: How might future missions test these ideas?
AH: A mission to Venus to sample its atmosphere or to Mercury to sample the rocks on its surface and measure the isotopic compositions would be invaluable. However, it probably requires returning the samples to Earth for measurement in the laboratory in order to achieve the precision required. It would allow us to test 2 above. Such a mission is a long way off. It is conceivable that we have samples of Mercury in our meteorite collections but do not yet know it. Some have argued for this but the case for any particular group is not entirely convincing yet.

OSB: What continues to fascinate you about the Moon's origins?
AH: The Giant Impact became, not just a model about the Moon, but an example of a mechanism by which all of the terrestrial planets formed. Other impacts did not form moons that persisted but the process is thought to be fundamental to planetary growth. As such it goes to the heart of the issue of how Earth-like planets originate. Of course Earth's spin also gives it day and night and this plus the tidal effects of the Moon affect habitable environments. Therefore, understanding how the Moon formed goes to the heart of the issues of origins and how habitable Earth like worlds are formed.

Yet, today, hundreds of years after Galileo showed the world the mountainous features of the Moon and started modern observational astronomy, hundreds of years after John Wilkins and Robert Hooke at Oxford discussed how to build a space craft to visit the Moon, and went on to found the Royal Society, and decades after Armstrong and colleagues brought back those precious samples of lunar rock, we still do not have a satisfactory explanation for how the Moon formed.

This is a scientific issue of deep significance that needs to be resolved.

Last week, Arts Blog wrote about a brilliant video of student a cappella group Out of the Blue singing a close-harmony rendition of Shakira’s ‘Hips Don’t Lie'.

We waited a few days before putting the story up so that we could record the number of times the video had been viewed after the increase had slowed down. We settled on 660,000.

We should have waited longer – as of Thursday 7 August, nearly four million people across the world have watched the video whose proceeds are going to Helen & Douglas House, a charity which cares for children, young adults and their families.

The madness began when Shakira sent her approval of the video on Facebook and Twitter. As the first person to receive 100 million likes on Facebook, this gave the boys an enormous audience.

Shakira

The video has received truly global coverage from media outlets in the USA, India, Brazil, Germany, France and many more countries. There have been hundreds of articles about the video, including pieces in French broadsheet Le Monde and India’s Hindustan Times.

Hindustan Times

Le Monde

It is lucky Oxford University undergraduates are on vacation because Out of the Blue, who are now performing at the Edinburgh Festival, have been in high demand all week. Marco Alessi and Ollie Nicholls were even interviewed on America’s National Public Radio.

Out of the Blue

The frenzy might not be over for the Oxford students. Cosmopolitan magazine suggested the group would be the ideal stars for another Pitch Perfect movie, a hit musical comedy about competing a cappella bands. Actress Elizabeth Banks, who directed Pitch Perfect II, seemed receptive to the idea.

Cosmopolitan

Elizabeth Banks

We have a feeling this story is not over. Watch this space...

The packed stadiums across Brazil during the World Cup – and the public outpouring of grief after their 7-1 defeat by Germany – confirms just how popular football is in Brazil. It is less well known that football was brought to Brazil by an Englishman – or was it a Scotsman?

Simão Valente is a Portuguese Lector in the Faculty of Medieval and Modern Languages, whose research focuses on crime fiction in Portuguese. To engage his students, Simão uses the stories of key figures in Brazilian history and culture.

In the following blog post he explores the origins of football in Brazil.

'Charles Miller is widely regarded as the man responsible for introducing football in Brazil. The son of a Scottish railway engineer, John Miller, and a Brazilian of English descent, Carlota Fox, Miller was born in the upper echelons of São Paulo society.

Sent to school in Southampton at age ten, he remained there until February 1894, when he returned to São Paulo bringing two footballs and the book of rules of Association Football. Teams and matches were organized, drawing largely from the overwhelmingly white and British managers of local companies, factories and farms. Football in Brazil, as in most countries, was first a genteel activity.

But in April of that same year, Thomas Donohue, a Scottish dye worker in a textile factory in the gritty Bangu district of Rio de Janeiro, organized a match among fellow workers. Some of the players, reflecting the makeup of the factory, were black.

The first eleven-to-eleven match following the rules still accepted today was indeed arranged by Miller in April 1895, but the match that Donohue organized was the first to field working-class and black players in Brazil, according to historian Carlos Molinari.

In 1905, Bangu Atlético Clube became the first football team to field a black player at national competitions in Brazil, Francisco Carregal. This past June, a statue of Thomas Donohue was inaugurated in front of the headquarters of Bangu, as part of the reassessment of his part in shaping Brazilian football.

The history of Brazil is marked by sharp social inequalities grounded on class and race, an inheritance of colonialism and slavery. The more inclusive version of football practiced by Donohue in Rio has a deep resonance with the development of the game in Brazil and the role it has to this day in Brazilian society.

It paved the way for the rise to stardom of Pelé, from the 1958 World Cup onwards. The Brazilian victory at that Cup brought unprecedented global visibility to a young black Brazilian, who had grown up in poverty, famously learning how to play by kicking about socks stuffed with newspapers. Millions of underprivileged Brazilians had found a hero.

The widely covered demonstrations in Brazil in the months leading up to the World Cup were primarily directed against government corruption and mismanagement. Part of this mismanagement, protesters argued, was the overspending in a sports event that, due to the prohibitive prices of tickets and the industry set around the matches, would not be enjoyed by common Brazilians, 20% of whom live below the poverty line.

It was a reaction against the gentrification of a sport whose character is so intimately tied to the national self-image, a connection to which Donohue greatly contributed.

The spectacular end of the Seleção in the Cup led to the current period of self-reflection in Brazil, commentators arguing that it may contribute to rekindling discontent as elections loom in October.

While their pride may have been hurt, the swiftness with which Brazilians turned to self-effacing jokes after the 7-1 loss to Germany is a sign of their evolving relationship with football. The devotion and enjoyment will still be there, but the cultural politics of the game cannot be ignored.'

As we report the spread of drug-resistant malaria parasites on our news pages today – and the scale of the threat this poses to global efforts to control malaria – two other studies published today by Oxford University researchers report promising results in developing new drugs and vaccines against malaria.

While neither set of results will provide a solution in the short term, it does show there are a range of efforts in the pipeline that are showing potential against this most difficult of parasites to tackle.

It is Oxford researchers based in Thailand that have reported the spread of parasites resistant to our best anti-malarial drug, artemisinin. The same team has been involved in running a clinical trial of a new drug developed by the pharma company Novartis. The drug is currently called KAE609 and works against the malaria parasite in a new way.

'The growing menace of artemisinin resistance threatens our current antimalarial treatments, and therefore our attempts to control and eliminate falciparum malaria,' says principal investigator Nick White, who is a professor of tropical medicine at Oxford University and based in the Mahidol Oxford Tropical Medicine Research Unit (MORU) in Bangkok.

'This is why we are so enthusiastic about KAE609; it is the first new antimalarial drug candidate with a completely novel mechanism of action to reach Phase 2 clinical development in over 20 years,' he says.

A child with malaria in Kenya

Copyright © Alex Kamweru / Oxford University Images -- All rights reserved.

The phase 2 clinical trial the Thailand group ran gave a three day course of the new KAE609 drug to 21 adult patients with uncomplicated malaria.

The results, published in the New England Journal of Medicine, showed rapid clearance of the parasites from patients' blood - a median time of 12 hours – including in patients with artemisinin-resistant infections. The main side effects observed were nausea and vomiting.

Novartis are now planning the next stage of clinical trials of the drug to continue to test the safety and effectiveness of KAE609. The study was supported by the Wellcome Trust, Singapore Economic Development Board, and Medicines for Malaria Venture.

Meanwhile, scientists in another of Oxford's overseas research programmes have identified a number of new malaria vaccine candidates.

The researchers in Kenya studied the immune responses of 286 children to a large number of proteins from the malaria parasite.

Writing in the journal Science Translation Medicine, the group was able to identify the antibody responses that most protected the children from malaria, and which of the many parasite proteins the children's antibodies latch on to.

Knowing which proteins to target could allow more effective malaria vaccines to be developed against the blood stage of the disease, they say.

'This study presents us with a large number of new vaccine candidates that offer real hope for the future,' says lead scientist Dr Faith Osier. She is based in Kilifi on the Kenyan coast - part of the joint research programme involving Oxford University, the Wellcome Trust and the Kenya Medical Research Institute. 

The scientists followed a group of children infected with malaria over a six-month period. While some patients became sick, others were protected by naturally occurring antibodies. The antibodies stopped the malaria parasite from penetrating their red blood cells during the blood stage of the disease.

'Each year, hundreds of thousands of people die from malaria; but hundreds of millions are infected, many of whom are protected from severe symptoms by their immune response,' explains Professor Kevin Marsh of Oxford University and director of the KEMRI Wellcome Trust Research Programme in Kenya.

The researchers, collaborating with scientists at the Wellcome Trust Sanger Institute near Cambridge, used samples taken from these children to identify combinations of antibodies that provided up to 100 per cent protection against clinical episodes of malaria.

Crucial to this study, funded by the Wellcome Trust and the Medical Research Council, was a library of parasite proteins generated using a new approach developed at the Sanger Institute. Dr Gavin Wright and Dr Julian Rayner were able to produce large numbers of correctly folded, full-length proteins from the Plasmodium falciparum malaria parasite – in particular proteins involved in the invasion of human red blood cells. This allowed the immune response to the proteins to be studied in the lab much more easily.

Oxford University's Botanic Garden is planning a send-off for the iconic black pine known as 'Tolkien's tree', which needs to be removed from the Garden after two limbs fell from the tree on Saturday.

The tree, a Pinus nigra, was a favourite of J R R Tolkien during his time in Oxford and some say its twisting branches resemble the 'ents' in his The Lord of the Rings novels.

Experts at Oxford City Council and Oxford University have decided the tree needs to be cut down. The decision was unavoidable but it does mean scientists can finally solve the mystery surrounding the tree.

Dr Stephen Harris of Oxford University’s Department of Plant Sciences explained: 'The received wisdom regarding the black pine is that it was planted in 1799 from seed that was collected by the Third Sherardian Professor of Botany, John Sibthorp, in Austria.

'We know that Sibthorp sent considerable amounts of plant material to Oxford from the eastern Mediterranean in 1786/87 and that he was in Austria in 1785. He was also in regions of Black Pine growth in 1795 but he died in 1796.

'If the story of the Black Pine is true then it should be at least 215 years old. The pine having to be cut down means that we have the opportunity to date the tree precisely and determine whether Sibthorp is likely to have been involved. The particular subspecies of Black Pine represented by the tree has also been a point of controversy - we should now be able to settle this controversy as well.'

The Garden has rigorous safety checks in place and every tree in the Garden is inspected annually. The area around the tree was evacuated before the limbs fell. The Garden will remain open while the work takes place, but the area around the tree will be cordoned off for the next few weeks.

Dr Alison Foster, acting director of the Garden, said: 'The black pine was a highlight of many people's visits to the Botanic Garden and we are very sad to lose such an iconic tree. We intend to propagate from this magnificent tree so that future generations will not miss out on this important link to Tolkien. We are considering using the wood from the black pine for an educational project along the lines of the One Oak project and hope to hold a celebratory event to commemorate the tree and its many associations in due course.

'I'd like to praise my staff for taking swift action to evacuate the area before the limbs fell from the tree and we assure visitors that all the trees in the Garden are subject to annual inspections by experts. The Garden will remain open over the next few weeks but the area near the tree will be inaccessible while work takes place. We apologise to visitors for the inconvenience this causes and we hope to reopen the entire Garden as soon as possible.'

Dr Stuart Lee, an English academic at Oxford University who has studied the fiction and manuscripts of Tolkien and ran the 2013 Tolkien Spring School in Oxford, said: 'Tolkien hated the wanton destruction of trees for no reason but it sounds to me like this is for all the right reasons so whilst this is sad news, it is inevitable.

'It is often said that the black pine inspired the 'ents' in Lord of the Rings, and it may be he liked the tree and saw something it in that inspired Treebeard, but in fact the ‘ents’ have many sources and ‘ent’ means giant in Old English, and Tolkien’s love of trees goes all the way back to his childhood.'