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Humanity’s quest to discover the origins of life in the universe

sc604 — Wed, 08 Mar 2023 17:10:32 +0000

For thousands of years, humanity and science have contemplated the origins of life in the Universe. While today’s scientists are well-equipped with innovative technologies, humanity has a long way to go before we fully understand the fundamental aspects of what life is and how it forms.

“We are living in an extraordinary moment in history,” said Professor Didier Queloz, who directs the Leverhulme Centre for Life in the Universe at Cambridge and ETH Zurich’s Centre for Origin and Prevalence of Life. While still a doctoral student, Queloz was the first to discover an exoplanet – a planet orbiting a star other than our Sun. ̽��ֱ��discovery led to him being awarded the 2019 Nobel Prize in Physics.

In the three decades since Queloz’s discovery, scientists have discovered more than 5,000 exoplanets. Trillions more are predicted to exist within our Milky Way galaxy alone. Each exoplanet discovery raises more questions about how and why life emerged on Earth and whether it exists elsewhere in the universe.

Technological advancements, such as the James Webb Space Telescope and interplanetary missions to Mars, give scientists access to huge volumes of new observations and data. Sifting through all this information to understand the emergence of life in the universe will take a big, multidisciplinary network.

In collaboration with chemist and fellow Nobel Laureate Jack Szostak and astronomer Dimitar Sasselov, Queloz announced the formation of such a network at the American Association for the Advancement of Science (AAAS) meeting in Washington, DC. ̽��ֱ��Origins Federation brings together researchers studying the origins of life at Cambridge, ETH Zurich, Harvard ̽��ֱ��, and ̽��ֱ�� ̽��ֱ�� of Chicago.

Together, Federation scientists will explore the chemical and physical processes of living organisms and environmental conditions hospitable to supporting life on other planets. “ ̽��ֱ��Origins Federation builds upon a long-standing collegial relationship strengthened through a shared collaboration in a recently completed project with the Simons Foundation,” said Queloz.

These collaborations support the work of researchers like Dr Emily Mitchell from Cambridge's Department of Zoology. Mitchell is co-director of Cambridge’s Leverhulme Centre for Life in the Universe and an ecological time traveller. She uses field-based laser-scanning and statistical mathematical ecology on 580-million-year-old fossils of deep-sea organisms to determine the driving factors that influence the macro-evolutionary patterns of life on Earth.

Speaking at AAAS, Mitchell took participants back to four billion years ago when Earth’s early atmosphere - devoid of oxygen and steeped in methane – showed its first signs of microbial life. She spoke about how life survives in extreme environments and then evolves offering potential astrobiological insights into the origins of life elsewhere in the universe.

“As we begin to investigate other planets through the Mars missions, biosignatures could reveal whether or not the origin of life itself and its evolution on Earth is just a happy accident or part of the fundamental nature of the universe, with all its biological and ecological complexities,” said Mitchell.

̽��ֱ��founding centres of the Origins Federation are ̽��ֱ��Origins of Life Initiative (Harvard ̽��ֱ��), Centre for Origin and Prevalence of Life (ETH Zurich), the Center for the Origins of Life ( ̽��ֱ�� of Chicago), and the Leverhulme Centre for Life in the Universe ( ̽��ֱ�� of Cambridge).

̽��ֱ��Origins Federation will pursue scientific research topics of interest to its founding centres with a long-term perspective and common milestones. It will strive to establish a stable funding platform to create opportunities for creative and innovative ideas, and to enable young scientists to make a career in this new field. ̽��ֱ��Origins Federation is open to new members, both centres and individuals, and is committed to developing the mechanisms and structure to achieve that aim.

“ ̽��ֱ��pioneering work of Professor Queloz has allowed astronomers and physicists to make advances that were unthinkable only a few years ago, both in the discovery of planets which could host life and the development of techniques to study them,” said Professor Andy Parker, head of Cambridge's Cavendish Laboratory. “But now we need to bring the full range of our scientific understanding to bear in order to understand what life really is and whether it exists on these newly discovered planets. ̽��ֱ��Cavendish Laboratory is proud to host the Leverhulme Centre for Life in the Universe and to partner with the Origins Federation to lead this quest.”

Scientists from the ̽��ֱ�� of Cambridge, ETH Zurich, Harvard ̽��ֱ��, and the ̽��ֱ�� of Chicago have founded the Origins Federation, which will advance our understanding of the emergence and early evolution of life, and its place in the cosmos.

ETH Zurich/NASA

L-R: Emily Mitchell, Didier Queloz, Kate Adamal, Carl Zimmer

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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Surface lakes cause Antarctic ice shelves to ‘flex’

sc604 — Wed, 13 Feb 2019 10:00:00 +0000

A team of British and American researchers, co-led by the ̽��ֱ�� of Cambridge, has measured how much the McMurdo ice shelf in Antarctica flexes in response to the filling and draining of meltwater lakes on its surface. This type of flexing had been hypothesised before and simulated by computer models, but this is the first time the phenomenon has been measured in the field. ̽��ֱ��results are reported in the journal Nature Communications.

̽��ֱ��results demonstrate a link between surface melting and the weakening of Antarctic ice shelves and support the idea that recent ice shelf breakup around the Antarctic Peninsula may have been triggered, at least in part, by large amounts of surface meltwater produced in response to atmospheric warming.

As the climate continues to warm, more and more ice shelves may become susceptible to flex, fracture and break up over the coming century.

Most of the Antarctic continent is covered by the Antarctic Ice Sheet, which is up to four kilometres thick and contains enough ice to raise global sea levels by about 58 metres. Over most of the continent and for most of the year, air temperatures are well below zero and the ice surface remains frozen. But around 75% of the ice sheet is fringed by floating ice shelves, which are up to a kilometre thick, mostly below sea level, but with tens of metres of their total height protruding above the water. In the summer months, when air temperatures rise above freezing, the surfaces of these ice shelves are susceptible to melting.

“Surface water on ice shelves has been known about for a long time,” said co-author Dr Ian Willis from Cambridge’s Scott Polar Research Institute. “Over 100 years ago, members of both Shackleton’s Nimrod team and the Northern Party team of Scott’s British Antarctic Expedition mapped and recorded water on the Nansen Ice Shelf, around 300 kilometres from where we did our study on the McMurdo Ice Shelf. For the last few decades, it has also been possible to see widespread surface meltwater forming on many ice shelves each summer from satellite imagery.”

What is not fully known is the extent to which surface water might destabilise an ice shelf, especially in warmer summers when more meltwater is produced. If the slope of the ice shelf is sufficiently steep, the water may flow off the ice shelf to the ocean in large surface rivers, mitigating against any potential instability.

̽��ֱ��danger comes if water pools up in surface depressions on the ice shelf to form large lakes. ̽��ֱ��extra weight of the water will push down on the floating ice, causing it to sink a bit further into the sea. Around the edge of the lake, the ice will flex upwards to compensate. “If the lake then drains, the ice shelf will now flex back, rising up where the lake used to be, sinking down around the edge,” said lead author Dr Alison Banwell, also from SPRI. “It is this filling and draining of lakes that causes the ice shelf to flex, and if the stresses are large enough, fractures might also develop.”

Banwell and co-author Professor Doug MacAyeal from the ̽��ֱ�� of Chicago had previously suggested that the filling and draining of hundreds of lakes might have led to the catastrophic breakup of the Larsen B Ice Shelf 2002 when 3,250 square kilometres of ice was lost in just a few days.

“We had been able to model the rapid disintegration of that ice shelf via our meltwater loading-induced fracture mechanism,” said Banwell. “However, the problem was that no one had actually measured ice shelf flex and fracture in the field, and so we were unable to fully constrain the parameters in our model. That’s partly why we set out to try to measure the process on the McMurdo ice shelf.”

Using helicopters, snow machines and their own two feet, the researchers set up a series of pressure sensors to monitor the rise and fall of water levels in depressions which filled to become lakes, and GPS receivers to measure small vertical movements of the ice shelf.

“It was a lot of work to obtain the data, but they reveal a fascinating story,” said MacAyeal. “Most of the GPS signal is due to the ocean tides, which move the floating ice shelf up and down by several metres twice a day. But when we removed this tidal signal we found some GPS receivers moved down, then up by around one metre over a few weeks whereas others, just a few hundred metres away, hardly moved at all. ̽��ֱ��ones that moved down then up the most were situated where lakes were filling and draining, and there was relatively little movement away from the lakes. It is this differential vertical motion that shows the ice shelf is flexing. We’d anticipated this result, but it was very nice when we found it.”

̽��ֱ��team hope that their work will inspire others to look for evidence of flex and fracture on other ice shelves around Antarctica. Their work will also help in developing ice sheet scale models that could be used to predict the stability of ice shelves in the future and to understand the controls on ice shelf size since they act as buffers against fast-moving ice from the continent. As ice shelves shrink, glaciers and ice streams behind them flow more rapidly to the ocean, contributing to global sea level rise.

̽��ֱ��work was funded by the US National Science Foundation, the Leverhulme Trust, NASA, and CIRES, ̽��ֱ�� of Colorado, Boulder.

Reference:
Alison F. Banwell et al. ‘Direct Measurements of Ice-Shelf Flexure caused by Surface Meltwater Ponding and Drainage.’ Nature Communications (2019). DOI: 10.1038/s41467-019-08522-5

A bold response to the world’s greatest challenge
̽��ֱ�� ̽��ֱ�� of Cambridge is building on its existing research and launching an ambitious new environment and climate change initiative. Cambridge Zero is not just about developing greener technologies. It will harness the full power of the ̽��ֱ��’s research and policy expertise, developing solutions that work for our lives, our society and our biosphere.

̽��ֱ��filling and draining of meltwater lakes has been found to cause a floating Antarctic ice shelf to flex, potentially threatening its stability.

Filling and draining of lakes causes the ice shelf to flex, and if the stresses are large enough, fractures might also develop

Alison Banwell

Surface lakes on the McMurdo Ice Shelf

Yes

Professor Sir Christopher Bayly (1945-2015)

pbh25 — Thu, 23 Apr 2015 09:32:15 +0000

Professor Sir Christopher Bayly, described as the single most influential figure in the field of modern Indian history, has died in Chicago aged 69.

He was world-renowned for his enormous contributions to the Centre of South Asian Studies in Cambridge and to his subject.

He held many positions during his time at Cambridge including being the Centre’s Director, President of St Catharine’s College, and Vere Harmsworth Professor of Imperial and Naval History in the Faculty of History.

He also held positions outside of Cambridge including being the Vivekananda Professor at the ̽��ֱ�� of Chicago. It was on Sunday while in Chicago, during one of his annual Spring visits, that he died of a suspected heart attack.

Professor Bayly was a member of the Centre of South Asian Studies for more than 45 years having arrived in Cambridge from Oxford in 1969 where he had completed his doctorate under the supervision of Jack Gallagher.

Although he retired last year from the Directorship of the Centre he still maintained a base there and Professor Joya Chatterji, the current Director, said her predecessor was a “crucial point of continuity” in its history.

Professor Chatterji said: “It is not an exaggeration to say that Chris has been the single most influential figure in the field of modern Indian history. Every one of his monographs, from his first book on Allahabad in 1975 to his last book on Liberalism in 2012, broke new ground, whether in political, social and economic, or latterly intellectual history."

She added that Professor Bayly completely transformed people’s understanding of the 18th and 19th centuries in a series of publications, above all Rulers, Townsmen and Bazaars (1983) which many regard as his magnum opus.

Having established his reputation as a social and economic historian of outstanding originality, he then went on to take up new challenges. Empire and Information (1996) uncovered the worlds of Indian spies, runners and political secretaries who were recruited by the British to secure information about their subjects, and the social and intellectual origins of these informants.

Increasingly drawn to think about ‘world historical’ comparisons and connections he wrote first Imperial Meridian in 1989, and then a stunning new analysis of ̽��ֱ��Birth of the Modern World (2004), which transformed the understanding of the history of modernity itself, and drew attention to its richly complex, overlapping global roots.

A pair of books followed in quick succession, co-authored with Tim Harper, on the social transformations wrought by the Second World War in Asia. He would later write about the intellectual history of Indian liberalism.

Describing his work Professor Chatterji said: “His prodigious productivity, the stunning range of his scholarship, and his talent for thinking comparatively, and in a connected way, about a range of historical questions, established the reputation for which he was elected a Fellow of the British Academy in 2004 and received a knighthood in 2007.

“Many will remember Chris as an inspiring supervisor, as a colleague and friend, as a longstanding member of the Centre’s Committee of Management and above all as Director of this Centre.”

Reflecting on his legacy Professor Chatterji added that during his Directorship he oversaw the Centre’s move from its historic premises in Laundress Lane to the Alison Richard Building and launched the MPhil in South Asian Studies.

Professor Chatterji added: “No less significantly, he drew the study of South East Asia squarely into the Centre’s remit.

“Those who knew him have each, in their own way, learnt immeasurably from Chris, not only by reading his work, but by working with and alongside him as a supervisor and colleague. Our thoughts are with his wife Susan, his family, and his students past and present, who today feel bereft.”

Dame Jean Thomas, Master of St Catharine’s College, said that many people had paid tribute to Professor Bayly, adding: “It is clear that he was held in high esteem not only in Cambridge and St Catharine's, but around the world. We have lost a friend and valued colleague, and he will be sorely missed. We extend our deepest sympathy to Susan and his family.”

Friends and colleagues pay tribute to world-renowned expert.

“It is not an exaggeration to say that Chris has been the single most influential figure in the field of modern Indian history."

Professor Joya Chatterji

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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